The Electronic Frontier Foundation has setup a nice tool called Panopticlick. It demonstrates that web browsers have (almost) unique fingerprints. This was covered by wired, appeared on reddit and Twitter.

German readers found Panopticlick mentioned in ZEIT Online, ORF futurezone, and, of course, heise news. (By the way, I've seen it on ravenhorst first. Subscribe to Kai's blog if you want more like this.)

However, it seems nobody can remember the name. So I thought I'd help. It's Panopticlick!