A couple of sites that capture mobile UI design patterns have come to my attention recently. Lovely UI and Mobile UI Patterns both showcase lots of examples of mobile, both are useful just as a source of design inspiration. Unfortunately the sites are almost exclusively devoted to iPhone / touch UI, but hopefully that will change in the future.
Update: Steven Hoober noted that his upcoming book about mobile design patterns is available online as well at 4ourth Mobile Design Patterns Wiki. Lots of discussion of the patterns there, as well as schematic illustrations.