You can learn all the details and RSVP on the WhereCamp site.
What is WhereCamp?
Taken directly from the site linked above, "WhereCamp2009 is the unconference for hackers, mappers, thinkers, artists and anybody who wants to know their place. Hot on the heels of Where 2.0 we bring together up to 300 enthusiasts for two days of in depth discussion and hacking.
We are self-organized in true bar-camp style. Bring your projects, work and ideas to get feedback from a group of the worlds most passionate social cartographers. Topics are whatever you want them to be. Over the last two years we've seen presentations ranging from emergency crisis response such as the work http://ushahidi.com is doing, to local food such as http://www.serveyourcountryfood.net/ to psycho-geography to visualization, to mobile mapping to re-factoring urban landscapes."
When is WhereCamp?
Friday May 22nd and Saturday May 23rd from 9am to ~5pm
Where is WhereCamp?
WhereCamp2009 will be held at the SocialText Campus at 655 High Street Palo Alto, California.