The EFF is doing some measurement of browser uniqueness and privacy. It takes ten seconds.
Before you go, why not estimate what fraction of users have the same
transmitted/discoverable browser settings as you, and then check your
accuracy at https://panopticlick.eff.org. Or start at http://www.eff.org/deeplinks/2010/01/help-eff-research-web-browser-tracking for a bit more detail.