With a touch interface, accelerometers, and an online store that boasts over 100,000 apps, the Apple iPhone is fast becoming a mobile gaming device to compete with the likes of the Nintendo DS and Sony PSP.

But despite the App Store's "games" category enjoying more new releases than any other category in the last year, in September and October 2009, the most popular genre of new app published was book-related. Specifically, "In October, one out of every five new apps launching in the iPhone has been a book… The sharp rise in e-book activity on the iPhone indicates that Apple is positioned [to] take market share from the Amazon Kindle as it did from the Nintendo DS." (This may not be significant data, however, as many of the book apps are duplicates of public domain novels. For example, there are over 30 apps that offer Sun Tzu's The Art of War.)

The trend toward smartphones as e-readers may have already begun. Publishers Weekly recently printed a chart of who owns the e-book market. The iPhone and iPod together have captured 22%, which makes it the second most popular e-book reader, behind only the Kindle itself. It also makes Apple's product line 22 times more popular than the Sony eBook Reader.

Are Amazon and Barnes & Noble approaching the market the wrong way by hawking dedicated e-book readers? Why spend $259 on a Kindle when you can get a multipurpose iPhone 3G for $99?