Felix Turner, a Flash developer at Brightcove, built a super-nifty swirly, spinny “web 2.0-ish” Flickr picture browser that searches upon tags and returns its results in a nifty little UI.
Perhaps not mind-blowing, but it is fun, especially the way common search terms hover at the periphery of the window. That amused me immensely :-).
Felix also has a snazzy Flash-based, lightweight (12kb) photo gallery app that can be used on your website as well. The only downside to that sort of approach is that it’s impossible to get permalinks and the like functioning correctly, at least without a large amount of extra work.