I just wrote my first use of that <canvas> thing that everyone's talking about. (If you don't know, this is part of the WHATWG/HTML5 general vicinity of features: an element which creates a bitmap pixmap image that can be drawn on by JavaScript.)
Since LJ doesn't let me embed JavaScript or iframes (a restriction which I'm only just noticing...) I'll have to provide only a link (but your CPU meters will thank me for that):
Brownian Tree
(This is also part of a personal goal to learn more about Modern Web Applications technologies: “Ajax”, jQuery, web frameworks, etc. I used to (a) not have a personal server, and (b) tend to “All web content must be accessible to non-JS and pure-text users” — but I’ve come to realize that while one should still avoid unnecessary dependence on fancy stuff, there is value in using these systems to create what are not so much “web pages” as cross-platform, zero-install applications — they may not be usable by $NON-MAINSTREAM-BROWSER-TYPE but nothing else would be more compatible and still provide the same benefits.)