I had tentatively planned on attending OpenNMS Dev Jam this year, but then I got a new job, and it became mandatory.
The eighth annual Dev Jam will be held June 23-28 at the University of Minnesota.
NP: In Absentia, The Mars Volta
Datastax's yearly Cassandra Summit has grown into a two day event this year, June 11-12 in San Francisco. If you are a user of Cassandra (or are considering it), then you probably want to attend this conference (use code SFSummit25 for 25% off).
I'll be there to present on virtual nodes; Find me if you want to chat about databases, network management, beer, or the Can't Hug Every Cat phenomenon.
NP: The Malkin Jewel, The Mars Volta