Jake demonstrates his technique for preprocessor-generated stylesheets for older versions of Internet Explorer (while other browsers get the same styles within media queries).
If you use Sass, this could be a really handy technique for handling IE<9 support with mobile-first responsive designs.
This is your one-stop shop for envelope-pushing in the browser:
Brendan Dawes pointed me to this wonderfully playful creation. It's Flash-free, believe it or not.
Dave has been experimenting with processing and documenting the results here.
A very pretty little Twitter canvas experiment accompanied by music delivered via the audio element. View this in a capable browser.
Richard Feynman and The Connection Machine.
Infrastructure just got even cheaper. Between this and Amazon's EC2/S3, the barrier to entry to getting an app up and running is getting lower and lower.