The law is aimed at preventing wasteful spending by opening the federal budget to greater scrutiny. The information is already available, but the Web site would make it easier for those who aren't experts on the process to see how taxpayer dollars are being spent.
"Information on earmarks will no longer be hidden deep in the pages of a federal budget bill, but just a few clicks away," Mr. Bush said in a signing ceremony. "This legislation will give the American people a new tool to hold their government accountable for spending decisions. When those decisions are made in broad daylight, they will be wiser and they will be more restrained."
Mr. Bush signed the bill in the Old Executive Office Building next to the White House, sitting before lawmakers and Internet bloggers who helped get it through Congress.
Senate leaders had tried to pass the bill in early August but Rep. Ted Stevens, R-Alaska, and Sen. Robert Byrd, D-W.Va., blocked passage by lodging secret "holds" on the bill. The bloggers tracked down those responsible for the delay and the senators let the bill advance under the pressure.
The law calls for the Web site to go online by Jan. 1, 2008. It will list federal grants and contracts greater than $25,000, except for those classified for national security reasons.
"The Web site will allow our citizens to go online, type in the name of any company, association, or state or locality and find out exactly what grants and contracts they've been awarded," Mr. Bush said. "By allowing Americans to Google their tax dollars, this new law will help taxpayers demand greater fiscal discipline."