CommunityOne is the conference one day before JavaONE - in the same location. It's worth to attend.
Last year's sessions were really interesting. Beyond pure technology there was enough fun as well.
I really enjoyed the JSF / Sun SPOT Session about D.O.R.K (Dog Oral ...) an application which controls a "machine"
which feeds the dog, dependent on it's behavior - it was really funny (was this session actually recorded by someone on video?).
You have still chance to submit abstracts and present a session:
Close of call for participation: January 31, 2008
Notification of acceptance: February 15, 2008
Conference date: May 5, 2008 in San Francisco
The registration is free - and you get access to the J1 pavilion and general sessions and Tuesday, May 6. I'll try to attend as well (submitted some proposals already).
NEW: Online Workhop Effective WebApps without Frameworks is also coming to: MUC Airport.