Granted, many are useless while others are silly and senseless; a couple of competing apps make fart noises. One could write a book that cuts through all the clutter—in fact, that's exactly what Josh Clark did in his Best iPhone Apps: The Guide for Discriminating Downloaders (O'Reilly, July 2009, $19.99).

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The notion of a printed guide book covering something as dynamic as apps in an online app store that run on a deliciously digital device like the iPhone seems a bit outdated. It's akin to buying a two-day-old newspaper for a buck when you can get all the breaking news for free online.

That was my initial thinking when I picked up the guide book and read it over the weekend. But I quickly understood its value and Clark's reasoning behind its creation. There is an irony with longevity in a medium that changes by the minute: Only a handful of apps are really any good—and the good ones have staying power.

Clarks' guide breaks out 200 popular apps in seven categories: At Work, On the Town, At Leisure, At Play, At Home, On the Road, and For Your Health. I've listed some of Clark's choices in each category below.

The big criticism I have of Best iPhone Apps is that, in many cases, Clark doesn't go far enough in detailing the shortcomings of some apps.

For instance, one of his favorite apps for editing office documents is Quickoffice Mobile Office Suite (which happens to be mine, too). He adequately describes the main functions of the app, offers lessons on how to use the app in fairly non-technical language, and provides the app's logo and iPhone screen shots.

But the app has a major flaw, which Clark addresses in a mere two sentences: "Alas, the app can send but can't receive files by email (Mail won't let it read attachments, an unfortunate limitation.)" This means you can't edit received documents in Quickoffice (although you can view attachments in the iPhone's native mail app) and send out a new version. Yet this app bills itself as enabling iPhone users to edit office documents.