Did you have a New Year's resolution to organize your book collection (again)? It's definitely on the list in our household, but it's a daunting job; we have thousands of books (literally and literarily) scattered across many shelves, basement boxes and a home office, plus another whole library at my wife's office in desperate need of some database love.
A bit of luck, though: bibliophiles have a leg up on most other varieties of packrat, as almost all modern books have an ISBN, a number that purports to uniquely identify them. Capturing that ISBN may be a manual process for older titles, but for anything published in the last few decades there's almost certainly a UPC or EAN barcode on the cover with the ISBN encoded in it.
Getting serious about cataloging might prompt you to consider a Bluetooth hardware barcode scanner like the US$149 Intelliscanner mini, which can be used with its own bundled media database or with powerful software tools like Readerware, Book Collector or Bookpedia. One well-known Mac app lets you scan UPC barcodes with your Mac's iSight camera alone.
But you've already got a powerful camera attached to your touch and voice-activated pocket computer. Why not scan barcodes with your iPhone, and use them to populate your desktop catalog app? That's where the special talents of CLZ Barry ($7.99 for iPhone, also for Android) come into play.
CLZ Barry, made by the same folks behind the Collectorz.com Book Collector and other media database apps, is a barcode scanning app with a twist. The core functionality for scanning codes in Barry is built atop the RedLaser SDK, so it scans quickly and accurately. You can keep a running list of codes locally in Barry, and share them out via email, text message or iTunes download.
The magic is in the fourth sharing mode for scans: Barry cleverly pairs with a buddy application running on your Mac or PC. If both the iPhone and the computer are on the same WiFi network, your scans from Buddy instantly appear in the active text field of the foreground app, just as if you had typed the ISBN on the keyboard. Assuming your catalog app has a quick entry or multiple entry mode (all the ones listed above do), you can blithely scan away as you climb the ladders/dig in the boxes/roam the stacks, and have all the cataloging done by the time you get back to your desk. (Bruji's $3.99 Pocketpedia can do a similar trick, but only with the company's own desktop apps.)
This sounds a bit Rube Goldberg, but in practice it works extremely well. The iPhone's camera is plenty accurate for scanning, and the Barry app supports older hardware down to the iPhone 3GS and the fourth-gen iPod touch. You get clear audible and visual feedback on a successful scan, so you don't have to glance at your computer to see if the code made it over. I've tested Barry with both Bookpedia and Delicious Library, and it works great; a trifle slower than a dedicated USB handheld scanner, but more than adequate for the task.
Now, you could manage your entire book collection on your iPhone, but the biggest source of book catalog information won't necessarily be available. Back in 2009, Amazon began enforcing a restrictive clause in its API agreement that forbade licensees from using "Product Advertising Content" -- book images and descriptions -- on any mobile device app. This immediately put an end to popular iPhone apps like the iOS version of Delicious Library and Bruji's original Pocketpedia.
Pocketpedia 2 actually made it back to the store for about two months before Amazon sank it again; it was more than two years before Pocketpedia 3 arrived (with a new model for Amazon search that skirts the earlier issues), and it's coming up on its first anniversary this April.