For this event, we put a bit more effort into the design materials (and there's still some to come, with new t-shirt designs, badges, and such). If you're one of the people who care about organizing hackathons and making them successful, here's a little bit of additional background.
Here are a couple of design changes we made for this:
* New hackathon visual identity. We're still very much playing with different concepts, but here are a couple of logo variants:
http://commons.wikimedia.org/wiki/Category:Wikimedia_Hackathon_San_Francisco...
Our goal here was to harmonize the Wikipedia/Wikimedia visual identity into a single design that could represent technical events well going forward. We ended up with the hexagon design because we felt it can represent technical work and collaboration (connotations with chemistry, beehives, creative play) without resorting to the highly mechanical gears/rocketry/lightning/wrenches imagery that's often used.
The simple puzzle piece seemed like the least obnoxious way to incorporate reference to Wikipedia. We wanted to do that, because the Wikimedia-centric design of past events is great from an insider perspective, but if we're trying to bring in new people, we'd like to try some new ideas by connecting with the familiar WP brand.
We're going to use this for the SF event, but I'm very much open to further iteration for future WMF events. And obviously anyone organizing these kinds of events can make up a new design, but I hope you'll find these ones appealing.
* Featuring community profiles. Still mostly a placeholder with two staffers being featured, but hopefully we can expand on this. The point of this is, again, to introduce human beings into the design in a way that helps people understand that there's a community for them to meet and become part of.
Hope you like it, and if you see any obvious room for improvement (I'm sure the HTML/CSS could use some love), be bold :). Big thanks to Heather Walls for working on this for us.
Many thanks, Erik