Most of my new side projects end up on GitHub. Highlights at time of writing include CanvasLife, an implementation of Conway's Game of Life in Javascript and HTML5's canvas tag, and worksheets, and experiment in workbook-style interfaces to databases.
SilverService is a Mac OS X application that combines the power of the Unix command line with the convenience of the Services menu. It has its own page.
A list of older software I've written may be found here.