See bird. Look it up. Bird gone.
This is the usual sequence of events whenever we've tried our amateurish hand at birdwatching. That's why the pocket-sized "Audio Visual Handheld Bird Encyclopedia"--a specially outfitted Palm Tungsten E2--would be tempting were it not for its $450 price. (The regular PDA goes for around $200, and Palm's future might be a consideration if support is an issue.)
If you are so inclined, however, the Hammacher Schlemmer device is a treasure trove of birding information that's searchable by name, color, size, location and other parameters: 867 North American birds, 1,600 images, 650 range maps and "four hours of recorded birdsongs from the renowned Macaulay Library at the Cornell Lab of Ornithology." Yikes.
It can build community too. You can upload "birding checklists" from eBird.org, a site where you can also share information with other enthusiasts, such as fellow Craver an reknowned birder Harry Fuller.
But first things first. If you're a backyard birder, all of this is irrelevant until you can take care of the rodent issue.