Google has a new
project hosting service if the code is released under some various open source licenses.
A quick look shows real Subversion access, with issue tracking and web repository browsing. May be worth setting up a CodeCall project, and branching subprojects off of it. Only problem with that scenario is it makes the CodeCall project owner(s) responsible for adding folks for write access - and you can't give access to only subprojects.
Alternatively, each CodeCall project could set up their own project at Google, and have a sticky with the necessary information to check out/browse/view/commit/etc.