One thing to look out for is that if you are expecting lots of images and usage , most 'NIXs do linear scans of directories, meaning that with a lot of images, it can get very, very slow. If you ever used
Cache::FileCache you might notice the way it uses digests of the names (for fairly random distribution) and splits the storage into sub-directories. /dir/a/ab/abcd/abcdefghijk.gif
If you don't expect that kind of usage, I would just go the simple route. You can always modify it later. (Though if people are linking to this stuff, you might want to think about it now.)
-Lee
"To be civilized is to deny one's nature."