Just added two new entries to the Publishers offering databases for mobile devices section on the M-Libraries page of the Libsuccess wiki. I was surprised to learn that Questia still seems to be going strong after all these years. And the American Institute of Physics has also released an iPhone app called iResearch, which "is an offline e-reader that enables users to save PDF files locally to their device and view them offline without a Wifi or cellular connection. Users navigate through the journals, the volumes and issues to select an article they wish to read." The big problem with iResearch is that it checks only for an institutional IP address, which means you can't fully use it from off campus. 'Twould seem pretty easy for them to allow users to plug in a proxy server address to take care of this – we'll see what the next version brings.
Oh, and I also found this cute little Public Library finder app called Library, which you'd think would be relatively simple to find in iTunes but really really isn't! All it does is pop open Google Maps to show you the closest public libraries to your current location – seems fairly complete in the two cities I've tried it in. For finding stuff like this, I recommend AppMiner – it allows title and keyword searches, instead of just the default keyword search you seem to get in iTunes :-/