Fantastic Library (US$0.99, universal) is a slick iOS app that uses your camera as a scanner to grab and save information about your collection of books, DVDs, CDs and games. Note that the app is available in English, despite the German above.
To get started, just scan the bar code, and in a couple of seconds your stuff is complied in a database in the app. Items are automatically classified by type, or you can create your own categories. If you have something old without barcodes, you can manually enter in the information.
The app is reminiscent of the wonderful Delicious Library app for OS X ($25.00) that has a similar purpose. Originally, you had to buy a handheld bluetooth barcode scanner that talked to your computer, but now, as an option, you can grab the barcodes with an iOS device too, although all the identification and database stay on your Mac.
Fantastic Library provides details about each item, but Delicious Library will actually give you an estimated cost of your whole collection, which is great for insurance purposes. Both apps can keep track of things you lend to friends.
Using Fantastic Library is easy, and my results were good, even in a fairly dark room. You do have the option to use the camera flash for more light. Scanning was very accurate, and only a couple of really old books couldn't be identified. The app lets you search your library, and there is no limit to the number of items you can scan. You can sync the library to another iOS device running the app, or access your items in browser. Your collection can also be password protected.