This was linked on another forum I go on, but it's too awesome not to share.
If you're familiar with the Yamaha Tenori-on you'll love this site. If you've never heard of it check out the wiki entry
, its a pretty cool toy.
But basically someone has made a browser based version of it:
It's every bit as awesome to use as it looked in the demo vids I saw ages ago.
And if you're into your techno-synth stuff, then you'll love this:
(also allows you to use the Tenori-on!)