A frequent topic of conversation in the local-government sphere is the changing nature of libraries. As more and more books and research resources move online, what will libraries' roles be in the future? Barnes-and-Noble-esque hangouts in mixed-use developments? Multi-media production studios? Youth centers for kids to hang out and play video games?

One British librarian has another idea to throw in the mix: Libraries should take up the role of saving and cataloging digital information. The problem, says Lynne Brindley, the chief executive of the British Library, is that "digital memory" is fleeting -- and once a Web site is gone, it can be gone forever. As she wrote in the U.K. Guardian , what we end up with is a "black hole of history":

At the exact moment Barack Obama was inaugurated, all traces of President Bush vanished from the White House website, replaced by images of and speeches by his successor. Attached to the website had been a booklet entitled 100 Things Americans May Not Know About the Bush Administration - they may never know them now. When the website changed, the link was broken and the booklet became unavailable....

The 2000 Sydney Olympics was the first truly online games with more 150 websites, but these sites disappeared overnight at the end of the games and the only record is held by the National Library of Australia.

If websites continue to disappear in the same way as those on President Bush and the Sydney Olympics - perhaps exacerbated by the current economic climate that is killing companies - the memory of the nation disappears too. Historians and citizens of the future will find a black hole in the knowledge base of the 21st century.

You might think an online service such as Google is archiving sites like these, but they're not -- not in any routine or orderly way. The task, Brindley says, should be taken up by libraries.

Brindley's argument seems to center on national libraries, and it's easy to see how the U.S. Library of Congress could enact a digital archiving system.

But I can envision a role for local libraries as well -- cataloging sites from local government, public events, and so on.