I like the montager application, which creates one big image made out of lots of smaller images. I always imagined creating such a montage would be quite hard to do, but with Flickr you can do it instantaneously. ALIA used a montage image to advertise Library week this year, which looks like this:
Clearly someone at ALIA has done the libraries 2.0 program!
Using the trading card maker I made an incredibly witty librarian trading card. It looks like this: