BoingBoing says:

In April of 2010, Twitter and the Library of Congress announced they had partnered to create an archive of public Twitter — something Twitter does not offer directly to users. "Expect to see an emphasis on the scholarly and research implications of the acquisition," the LOC said on its blog, touting the plan as a sign of the Library's tech savvy: "if you’re looking for a place where important historical and other information in digital form should be preserved for the long haul, we’re it!"

Today, the Library has released a white paper explaining why it hasn't been able make an archive available. As of today, it says, the "Library has not yet provided researchers access to the archive," despite "approximately 400 inquiries."

It doesn't look like the archive is ever going to be truly functional, unless someone outside the Library of Congress steps in with a solution. At the moment, a single query could take as long as a day to find results. It is 2013, and there is still no good way to search Twitter's archives.