I just got back from a lunchtime briefing at Yahoo about their open Hack Day next Friday, September 29.

The basics: Yahoo Hack Day is a roughly 24 hour event beginning on Friday, September 29. This is open to any developer who wants to participate, although there is only room for 500 total hackers and 100 total projects (request an invitation on the Hack Day site). People attending Hack day can camp out at Yahoo, either by pitching a tent on the lawn or sleeping inside one of the buildings (I’ll be camping out on the lawn).

Coding ends at around 2:30 on Saturday and then every team will be given a couple of minutes to demo their project to a group of judges. Small prizes will be given to the “winners,” although the real purpose of the event is to collaborate and share ideas, not to take home a physical prize. I’ll be emcee’ing the demos and awards.

There are two parties, one on Friday evening and one on Saturday evening after the event is over. The entertainment lined up for Friday night is going to be incredible, although a non disclosure agreement prohibits us from saying who it is. I can say with confidence, though, that everyone attending the event will be very, very happy they were there for Friday night’s party.

There will be a ton of press at the event.

For information, see the Hack Day main site and blog, and my original post announcing it. Chad Dickerson, who runs Yahoo’s developer network, also has a couple of posts up about Hack Day on his personal blog. The Yahoo UI blog has a post up today with additional information, including a schedule. Robert Scoble, who was also in the lunchtime briefing, wrote about it as well.

See you next Friday!