From the article in Library Journal.com

On September 10, librarians are asked to “Slam the Boards!” by visiting online “answer sites” such as Yahoo! Answers, Ask MetaFilter, Wikipedia Reference Desk, or Amazon’s Askville, fielding as many questions as possible, and making it clear that the service was provided by a librarian. What began as a word-of-mouth idea has grown into an international effort, as librarians from the U.K., New Zealand, and beyond have joined the grass-roots effort in the U.S. to raise the profile of librarians and libraries that offer virtual reference services by doing what libraries do best—providing answers from authoritative resources.

I think this is a great idea, and I’m planning to participate.  Beyond making it clear that the information came from a librarian, though, I think it would also be great to include a statement about how many libraries offer online reference through chat, email, etc.  If someone is searching using Askville, they’re clearly comfortable seeking information in an online environment.  Unless we communicate to them that they can get better information in the same convenient manner, we’re unlikely to convince them to choose a librarian the next time.  So, when I write my answers, you’d better bet I’ll be plugging virtual reference services!