The next time you're oohing and aahing over the photographs in someone's flickr stream, stalk their camera!
Did you know that flickr can tell you the kind of camera the user shot their posted photos with?
On anyone's flickr photo page, you'll see the Additional Information column on the right side. One of the first bullets should be, for example, "Taken with Nikon D90," or whichever camera they used. Click on the camera's highlighted name, and you'll get a ton of details about that particular camera, (check out the Nikon N90), like how many megapixels it is, what the cost is, and what its ranking on flickr is (FYI, users can opt out of this, if you don't see it on a particular user's photo).
It's like advanced geek shopping.