As a hobbyist programmer, I've written several small utilities and screensavers:

Mac OS X Screensavers:
	ClockBox
	Just what the name implies; a virtual "box" of clocks that you can use to save your screen!
	Inferno
	Set your screen on fire with this hot new screensaver!
	Bubbles X
	A Mac OS screensaver inspired by the Windows flowBubbles screensaver
	MacStars
	Another just-for-fun Mac OS X screensaver - this time with sparking stars!
Web 2.0 Apps:
	iConvert
	An online icon converter to convert ico to png, png to ico, and many other formats to ico, icns, and png.
Linux / Open Source:
	libicns & icns2png
	A library for reading and writing Mac OS icons, with a tool for extracting PNGs from icns files.