Dear HN: What interesting algorithms would you like to read about?

I'm the author of the Damn Cool Algorithms series of posts (http://blog.notdot.net/tag/damn-cool-algorithms), a couple of which have been featured here on HN, and I'm looking at resuming the series on a more regular basis.

What algorithms do you think are 'damn cool' and not already sufficiently well written about in an accessible manner?