Today while reading some past posts of MakeUseOf.com, I found out about eReaderLookup.com. Do you have patrons asking you which eReader device they should buy? I know I do, and I hesitate to make a specific suggestion. I can certainly talk to them about which devices have which features, and help them decide which features they like by letting them play with the library's stock of devices, but ultimately they need to decide for themselves which device they like best. This site can definitely help facilitate that discussion - especially if your library does not have a stock of devices for people to play with. This site also makes for a good way to train your staff about devices because it makes it more clear which features are available in each eReader.
Here are some screen shots (click to enlarge):