Great in theory...

... but rubbish in practice.

Would be a convenient app, but each single ISBN I enter is looked up for a minute, an then the app closes itself.

Im using an iPhone 3G with most recent os.

A barcode scanning option would be great (like RedLaser).
So would be the option to import a list of ISBNs.

Sorry for only one star, but from my point of view, it just doesnt work at all (yet).

scmcg about iBookshelf Lite