First off, yes, I know that this is not an app per se but you can read books on it and you can’t export books from it, so for all intents and purposes it is a reader tool. (Although, a neat iPhone trick, if you didn’t already know, is that you can bookmark webpages to your homescreen so they appear like an app. Some, such as this, even have an icon all queued up, others will use a screen shot, so zoom in on the logo or whatever image you’d like before you make the bookmark.) Ultimately, that this isn’t an app is basically it’s undoing.  Google Book Search offers access to a whole lot of public domain stuff, and this optimization makes it easier to navigate the service on the iPhone, but you’re much better off getting the same titles through manybooks.net or Project Gutenberg and loading them into an app like Stanza.

For a web-based program, it works pretty well.  The navigation bar that stays at the top of each page (well, chunk of pagination) works as you’d expect, and it keeps a record of books you’ve accessed. Setting up your own library isn’t all that intuitive, so you’re better off not bothering. You pretty much have to read stuff in landscape mode, because keeping the iPhone vertical makes the formatting a bit funky, especially around indentations and images. Oh, and you can’t resize at all, even though you are technically in your browser. You can’t bookmark or highlight, and every time you open it it goes back to the main menu (but not before showing you where you were–ugh), which is something annoying you don’t have to deal with on apps. Also, being web-based it is noticeably slower than the other readers available for the iPhone, even over WiFi.
Really, the only nice thing about Google Book Search on the iPhone is the recommendations on the main page. On a computer, the two things that Google Book Search–despite annoying formatting–does have over the other freebie guys is the access to all the magazines they added not too long ago, and the ability to search for a line of text within their vast database. The former is noticeably absent from the mobile version, and while the latter still works in a pinch, I doubt people are doing much academic work with their iPhones that this will prove very useful outside of settling bet in a bar (assuming you’re a dork who makes bets about lines in books written at least 70 years ago). When it comes right down to it, Google Book Search does nothing on the iPhone that somebody and perhaps everybody is already doing with their apps. Supposedly, they are working out a deal to make an app version using Lexcycle’s Stanza as a base. With any luck this won’t be a standalone waste of homescreen space, but rather added (magazine?) functionality to an already solid program. They’ve also announced a partnership with Amazon on mobile devices.  Hopefully Google has bigger plans for their vast library of scanned books than merely “optimizing” the Book Search for iPhone.