[tomsem]

Bluefire will open .acsm files directly. You can email them as attachments to your iPad's mailbox for example, or using Dropbox.

It is also possible to have Bluefire open the .acsm directly on iPad from the library web site. Doing so may require using a 'bookmarklet' (javascript fragment) with Mobile Safari (at least it did last time I did this), though if I remember, other browsers (iCab) can do so by setting appropriate browser agent.

Or if you are frustrated by the whole .acsm thing, you can just get Kindle for iOS (or OSX) and use that to read library books. Doesn't cost anything to set up an Amazon account, no computer required. Any highlights and notes you make are saved to your Amazon account where you can get at them even after the book is returned, and unlike Bluefire (or other RMSDK-powered apps like Overdrive Media Console) you can pan/zoom images.