The Mozilla Foundation is holding a developer day. I might consider going, although it depends on how soon it is held. I could use the opportunity to actually go on vacation as well. And I'm sure the developer day would be fun even though I haven't been to any of the others. I had planned to attend the last one but I decided to quit my job instead.
Might be interesting to have an Mozilla end-users day too. Perhaps a Meet The Mozilla Firebird Developers Day. That would probably bring quite a few additional people by, therefore generating more interest. Anything to improve Mozilla and help spread the word is a good thing.