Here are some programmy things I have been exploring recently.
google-mobwrite is a framework for synchronising human edited text. It all integrates nicely with web pages through Javascript and the HTML textarea element (also other elements too), and also on the server side there are Python and other implementations of the protocol, including a ready-to-launch app-engine version. Very nice. I have implemented a very basic etherpad clone called txtfish using mobwrite.
processingjs.org is a basic Javascript and canvas element port of some of the Java-based proce55ing multimedia language/framework, magically called into being by the ultimate Javascript ninja, John Resig. This is cool because with the speedup in modern Javascript engines, it demonstrates the possible death of flash in the not too distant future, if we're lucky. Another cool and vaguely similar project is Raphael, although I haven't tried it yet myself.