Recently the guys from Soundcloud made some nifty updates on their site, including extended features for a better handling of CC licensed material, refined tag search, etc...
Read the details in their blog: blog.soundcloud.com

Paulstretch is one of my favourite tools for producing drones and pads. It is able to perform Timestretching up to factors beyond x1000 at a pretty excellent quality.

Got an hour? Enjoy Beardyman's funny and creative live performance...

This blog entry is about pitching/timestretching theory and explains the advantage of using the Speed method to minimize pitch/stretch sound artifacts. There's also a link to an interactive online table where you can look up attributes of samples to be transformed by the Speed method.