Scripted image manipulation: I wrote a script that builds seamless background images out of sets of smaller images, kind of like contact sheets. This started for a comic book themed web site so that the background image could be a collage of comic covers with a special theme ( Christmas, celebration of a comic artist, ...etc. ) I am still cultivating the script so that it'll be friendly enough for public use. I'll place it on Github when that happens.
Little Languages: I like to tinker with my own compilers / interpreters. I had read an article recently about someone building an example Linux shell and I wanted to try a couple of ideas where I thought I'd take a different approach than the author. I ended up building a very, very tiny BASIC interpreter in C. My proof that the interpreter was "good enough" was whether or not I could write a script in the dialect of BASIC to display the lyrics to the song "The Twelve Days of Christmas."