I made a very small & simple image gallery script. It's just one file you need to upload to your webserver. (But you still need your ftp-client for uploading the images) I know there are millions of these kinds of scripts, but if someone finds this useful, it's all good! :)
I've created even simpler image gallery, which uses only html and javascript. The downside is that you have to add the images manually into the file. And it requires javascript supported browser. The javascript part of the file is commented, so if you want to learn some javascript, thats a good place to learn.
But it's simple. :)
You find the simplified gallery from the same place, here