I am a frequent contributor to Node.js and a less frequent contributor to many other open source projects.
Create a playlist of songs with common musicians. Like Six Degrees of Kevin Bacon but for music. Sort of. Hosted at http://musicroutes.com/.
Search all the things!
Generate Benedict Cumberbatch-like names such as Banjodad Muffinrats and Barbertruck Muffinbeach.
While running Music Routes, I collected a ton of data about what musicians play on what tracks. I decided that I shouldn't bogart that information.
Generate metal band names such as Twisted Vengeance and Desecrated Glory.
Visualiations for the data above.
Just for fun. Web conferences should probably have a snappier interface and more gee-whiz features. Why don't you open a pull request, smarty-pants?
Need to monitor the time setting on a web server that you don't have access to? Let clockdrift.js do it for you!
My-Radar is a Google App Engine web app that lets you allow others to track you on a map.
Make mobile/tablet sites/apps quickly. Geared towards resource-strapped higher education, but useful for anyone.
You know that delay of a few hundred milliseconds on touch devices when you're browsing the web? Use Lightning Touch to get rid of that delay on your site.
Are you frustrated by the incompatibilities between responsive image solutions (like picturefill) and HTML5 offline appcaching? Pickyfill may ease some of your pains. (Unless you need those pains eased on Android 2.3.)
Some ideas on getting started contributing to Node.js. Contains many Muppet slides.
Not actually about curing cancer or even really HTML5. It's about federated search and Amalgamatic. HTML5DevConf, October 2014, San Francisco.
MMWCon, September 2013, Los Angeles.
Mobile web performance as well as a few not-necessarily-performance things to do to make your mobile web site not suck. MWF Conference, September 2012, Los Angeles.
Short-ish talk on frequent release strategy for websites, with Michele Mizejewski.