In reply to snowcat:
Desert climbing is good at that time of year and there's loads of good (and very beautiful and remote) bouldering areas in and around the Anza Borrego. I agree with many of the suggestions already made (although I haven't yet made it to the slot canyon - it's on my list). J Tree is a couple of hours away and is must-do, even on your own (there's always Gunsmoke). Suicide / Tahquitz is brilliant but may be anything from a bit parky in the shade to full winter conditions in January depending the weather - worth going for the hiking anyway.
I'd really recommend Mount Woodson - fantastic granite bouldering and brilliant one pitch trad cragging if you can find a partner. Cracks and slabs a speciality. Santee is OK local suburban bouldering (a bit like Caley), McCain Valley is bit difficult to figure out without some local help and seems to involve some bhundu bashing to find things. I've only been to Mission Gorge on my own and I thought it was a bit scary as a bouldering /soloing venue but probably quite good with a rope.
Try to get hold of the Dave Kennedy / Chris Hubbard San Diego County Climbing Guide and see if you can find the problem on the front cover (Forca). And then see if you think it's V4!
Get in touch and you can borrow my guide, as long as I get it back!