MySpace, the country’s largest social-networking Web site, has agreed with attorneys general of 49 states to take new steps to protect children from sexual predators on its site. It also agreed to lead a nationwide effort to develop technology to verify the ages and identities of Internet users, officials announced Monday.

The agreement is the latest attempt by law enforcement officials nationwide to shield children from online dangers, including the risk of encountering inappropriate sexual content or receiving sexual advances through sites like MySpace and Facebook. The sites, increasingly popular among college, high school and even younger students, allow any Internet user to create a profile to display personal information and build networks of friends online.

Richard Blumenthal, the Connecticut attorney general, announced the deal at a news conference in Midtown Manhattan, along with a MySpace executive and Roy Cooper, the attorney general of North Carolina. Also present were Attorney General Anne Milgram of New Jersey and the attorneys general of Pennsylvania and Ohio.

Mr. Blumenthal said the voluntary agreement went further than the one struck in October between New York’s attorney general, Andrew M. Cuomo, and the Facebook Web site.

“It’s stronger, broader, a very significant step or even a milestone in making the industry aim higher to keep kids safer,” Mr. Blumenthal said in an interview.

He cited steps in the new agreement to separate children’s profiles from those of adults and to seek ways to verify users’ ages — steps that he called for after the Facebook agreement, when he and Mr. Cooper had said that stronger measures were needed.

Mr. Cuomo said the MySpace agreement built on Facebook’s acknowledgment that it bore responsibility for protecting users.

“The Facebook agreement broke the ice,” he said.

The most important new measure, Mr. Blumenthal said, is that MySpace will create and lead a task force to find ways to verify ages and identities online. The task force, which will receive input from competing sites, child protection groups and technology companies, will report back to the attorneys general quarterly and issue recommendations at the end of this year.

Facebook, in its agreement with New York prosecutors, promised to respond more speedily to complaints about sexual messages and to warn users in stronger language that the site could not guarantee children’s safety.

The new agreement with MySpace, signed by 50 attorneys general — the top prosecutors of the District of Columbia and every state except Texas, includes similar provisions, and more.

“This is an industrywide challenge, and we must all work together to create a safer Internet,” Hemanshu Nigam, the chief security officer of MySpace, said in a statement.

MySpace, which says it has about 70 million users, agreed to install safeguards that require an adult user to prove that he or she knows a child user in order to contact that child, for instance by typing in an address or phone number.

Profiles of users under 18 will automatically be set to “private,” preventing casual browsers from seeing them.

The Supreme Court did not explain its decision to leave the appeals court ruling undisturbed. Chief Justice John Roberts did not take part in the action.

The Abigail Alliance for Better Access to Developmental Drugs and the Washington Legal Foundation sued the FDA in 2003, seeking access for terminally ill patients to drugs that have undergone preliminary safety testing in as few as 20 people but have yet to be approved.

Abigail Alliance was created by Frank Burroughs, whose daughter, Abigail, was denied access to experimental cancer drugs and died in 2001. The drug she was seeking was approved years later.

The alliance said all it was asking for "is a right for terminally ill patients with no remaining treatment options to fight for their own lives."

The FDA said the appeals court was correct and in line with other rulings "that have rejected constitutionally based demands for access to unapproved investigational drugs."

The full U.S. Court of Appeals for the District of Columbia Circuit ruled against the alliance after a smaller panel of the same court held that terminally ill patients may not be denied access to potentially lifesaving drugs.

The court said patients can access experimental drugs in certain situations and suggested Congress could change the law to broaden such access.

Democrats who are challenging the law say it uses prevention of fraud as a pretext to discourage elderly, poor and minority voters — those most likely to lack proper ID and who tend to vote for Democrats.

Opponents say there have been no Indiana prosecutions of in-person voter fraud — the kind the law is supposed to prevent.

A federal judge who upheld the voter ID law pointed out that opponents were unable to produce evidence of a single, individual Indiana resident who had been barred from voting because of the law.

Courts have upheld voter ID laws in Arizona, Georgia and Michigan, but struck down Missouri's. Wednesday's case should be decided by late June, in time for the November 2008 elections.

The justices could use the case to instruct courts on how to weigh claims of voter fraud versus those of disenfranchisement.

The Supreme Court was bitterly divided, 5-4, in 2000 in Bush v. Gore, the case that clinched the presidential election for George W. Bush.

The consolidated cases are Crawford v. Marion County Election Board, 07-21, and Indiana Democratic Party v. Rokita, 07-25.

In a 7-2 ruling, the justices said Metamora-based John R. Sand & Gravel Co. waited too long to sue the U.S. Environmental Protection Agency for property it seized as a Superfund cleanup site.

Justice Stephen Breyer said a federal appeals court was correct in raising the deadline question without being asked to do so by either party, and to rule that the company missed the deadline.

In some instances, such as lawsuits against the government, the Supreme Court "has often read the time limits ... as more absolute," Breyer wrote.

Justice John Paul Stevens dissented, saying the majority's decision "has a hollow ring" because the court previously had overturned a precedent that it relied on for Tuesday's decision.

Justice Ruth Bader Ginsburg joined Stevens in dissent.

"We're very disappointed in this ruling," said Jeff Haynes, a Bloomfield Hills attorney who represented the gravel company.

The decision ends the company's chances to collect any compensation from the EPA and will prompt other claimants to sue "early and often" to avoid a similar fate, Haynes said.

John R. sued the EPA in 2002 after the agency permanently fenced off 40 acres of land the company was leasing from a property owner.

Some of the seized property had been used as a municipal dump until about 1980 and was considered a hazardous waste site, although a portion contained clean sand and gravel, Haynes said.

The case initially was filed in the U.S. Court of Federal Claims, which hears claims involving the taking of private property without fair compensation.

The high court reviewed an appeal panel's finding that the John R. suit was barred by the six-year statue of limitations.

The EPA originally agreed that the case had been filed in a timely manner and didn't raise the statute of limitations issue, Haynes said.

But companies hired to clean up landfills intervened as friends of the court and raised the jurisdictional question, he said.

The appeals panel and the Supreme Court held that the clock started running when the EPA began erecting a series of temporary fences -- not when it permanently seized the 40 acres, Haynes said.

The effect of the high court's ruling is that judges at each step in the process will have to rule on time-limit issues in cases brought for money damages against the government, he said.

And anyone who wants to sue the federal government for taking private property without compensation will have to bring their claim as early as possible or risk having it tossed out, he said.

"We'll have a lot more needless lawsuits because property owners are going to have to protect their rights," Haynes said.

The Supreme Court didn't consider whether John R. was entitled to compensation by the EPA.

Haynes said the company valued the confiscated land at $8 million, while the EPA valued it at $250,000.

The main problem, the court was told, is the second drug in the sequence, which paralyzes the muscles. If the inmate is not properly anesthetized, the paralytic could mask whether the condemned is in tortuous pain.

Justice John Paul Stevens said he was "deeply troubled" by the use of the second drug, but that there was nothing in the record in the Kentucky case that raised the issue in a way for the Supreme Court to make a definitive ruling. Kentucky, he said, seemed to have done a good job of administering the drugs in the state's only execution by lethal injection.

Justices David Souter and Stephen Breyer also said it might be better to send the case back to lower courts for a comparative analysis of whether the three-drug process carries more risk than an alternative, which uses only a massive dose of a barbiturate.