One more Flickr toy: flickReplacr.
It’s a bookmarklet that seems to work fairly well in IE and Firefox/Mozilla (Safari – not so much). What does it do? You can highlight any word on any web page, click the flickReplacr bookmarklet, and the word gets swapped out with a random image from flickr that was tagged with that word. So “apple” becomes a 75×75 image of an apple.