I'm back from a short vacation without Internet access and thus working hard on catching up with reading emails, RSS feeds etc. etc.
Most notable finding so far (which is on my "read ASAP" list): Data Mining 101: Finding Subversives with Amazon Wishlists.
(via Boing Boing)
You can use this to find out where the visitors of your site come from (similar to GEOLOC and HitsMaps/ClustrMaps). The cool thing about it is that it uses Google Maps to display the visitors' position, which means you can zoom in and out as you see fit, and you get real satellite maps of the area. Now, is this cool or what?
See my stats for an example.