A slightly paraphrased account of the creation of a 20% project at Google, and an illustration of why I love working there:
Dan: I want you to write a wrapper for VML, SVG and Canvas
Glen: Let me handle this, 99
Dan: Sorry, Max
Glen: As I was saying, I want to write a wrapper for VML and Canvas
Erik: Good thinking, Max
...
Glen: How about *this*?
Erik: Just make it emulate the Canvas API in IE - all the other browsers support it anyway.
...
Glen: How about *this messy hodgepodge that sort of works*?
Erik: You young whippersnapper! I'll show you how it's done!
...
Erik: How about *this*?
Glen: Ooooohh!
...
Glen: Now I made it do images, hooray for me!
Erik: Except they don't work
Glen: Berrrrrrr
...
Emil: Hey world, look what I've been working on! Canvas for IE!
Erik and Glen: !! Join our secret project !!
Emil: Tally ho!
...
Erik: Look, I made it better!
Emil: Look, I made it even better!
Erik: Look, I made it even more better!
Emil: Look, I made it even more super better!
Glen: ... I broke it
...
Glen: Dearest engineering director Linus, look, we made bright shiny things!
Linus: K-Rad, doodz. Tell DiBona
Glen: Chris, look, we made bright shiny things!
DiBona: Open source!
...
Erik, Emil, Glen: Hello World, please enjoy ExplorerCanvas, we hope you find extra tasty uses for a what is now a cross-browser (Firefox, Safari, Opera 9, IE) drawing API.
To start you off, bodytag is hosting one of the included demos.
[Updated because I forgot about Dan]