Next to Magnadoodle, the Spirograph was my favourite toy as a kid. Many was the day I would sit aimlessly spinning pretty patterns while the rest of the boys were out playing football. Now it's possible to recreate these captivating images on your PDA using PSpiro Graph, a Palm app that lets you produce symmetrical sprial drawings.
The program itself includes a number of settings that allow you to change the structure of the design, save your pictures in your device's memory, share them with other handhelds, among other possibilities. It's pretty easy to use, although not as much fun as the original, as it feels that your control over the final outcome is limited somewhat.
PSpiro Graph provides an amusing distraction for creative Palm users, though ultimately you'll find the program quite restrictive.