I've sent out announcements on our internal mailing lists, and I'll pass it along to a few others in the near future.

I'll also give the site a mention in a few of my upcoming talks.  The site is a good example of new ways that the web can positively affect work in theory by speeding progress and letting us rapidly close or open new avenues of thinking, which certainly merits mention at the tail of a talk. This is doubly appropriate in cases where the site helps in investigating a problem.