You can now collect a bounty for implementing various features in Zap, the Mozilla codebase’s SIP stack.
This may be a good way to go for someone who has missed out on the Summer Of Code. And unfortunately, with around 100 serious applications and (it seems) only 12 places, there are going to be a fair number of people in that category. The deadline for us to finish the choosing process is 8am PST today; I presume the selected projects and people will be announced fairly shortly after that.