Cascaded revision control strategy
Okay, this isn't rocket-science, and in fact it's not even my idea (heard it on the FLOSS POD about Git). A problem with centralised repository systems such as Subversion (which is used on SourceForge) is that you need network access to do many things, and also to just save your work. You can't do commits to the repo' while on the train, for instance (which is where I do most of my hacking).
One option is to switch to a distributed revision system, such as Git or Mercurial. I may do that some day, but right now is not a good time for me to be learning a new revision system. Plus to have SourceForge host my project in Hg (for instance) means installing it myself and blah-blah-blah. Then there's IDE integration to consider...
I want to have my cake and eat it too.