The Humanities and Technology Camp, better known as THATcamp, will be held for the third time on May 22-23, 2010. THATCamp is a user-generated unconference on digital humanities organized and hosted by the Center for History and New Media at George Mason University. Deadline for applications is March 15.
According to Wikipedia, an unconference is a conference where the content of the sessions is created and managed by the participants, generally day-by-day during the course of the event, rather than by one or more organizers in advance of the event. An unconference is not a spectator event. Participants in an unconference are expected to present their work, share their knowledge, and actively collaborate with fellow participants rather than simply attend.
For more information and to apply, see http://thatcamp.org.