Phatch, written by Stani (author of SPE, Stani's Python Editor) is probably the nicest open source program I've used this year. I'm no great shakes with graphics, but I wouldn't even have been able to think about doing the transormations to my profile image that you see on the right.
The graphical interface makes it easy to perform the same operations on a bunch of different images in the same directory, and the flash image that comes up at the start always gives me a smile. Still in need of development, but definitely recommended, particularly if you have a lot of images to work on.
Needless to say, this little whizz is written in Python.
