Go to gaim.sourceforge.net and read about how to install cvs, I think they have nightly updates, and you can rebuild to the newest version any time you want. You might want to apt-get remove gaim before you mess with the cvs, also you should be familiar with cvs and compiling source to do this. If you decide not to use cvs you can still get the newest source and binaries from the page (I think cvs is undergoing major changes now) or you could always just try apt-get install gaim after you've removed it you may get a newer version but you'll probably lose your settings.