How about using some CVS?
its better than downloading tarballs everytime.
Why bother with CVS/SVN for a project that literally has one developer? CVS and SVN are excellent at keeping track of changes (and who made them) so it's easier to work together as a team. Sure, on the client side it lets you update *just the files* that have been updated, but I maintain a per-file changelog (which soon hopefully will be integrated into a single changelog).
And besides, you're going to download everything uncompressed via CVS/SVN, so it'll actually take longer to download it all. (at least the first time)
That said, if I get another developer on the team (my other "dev" is more of an idea generator and tester...though he knows MySQL much better than I do haha), I'll probably go with SVN.