An incredibly dim lightbulb went off for me this morning about the iPad, iPhone, iWhatever. It never occurred to me that Apple's app and book DRM would work the same way their other media DRM works, in that you can share with 5 authorized computers.

I find all DRM annoying but as much as I love the Kindle, it is very locked down in that you can not share a book with ANYONE.  I can understand the desire to not have your books posted all over the intertubes for free, but the fact that I could not lend a book with someone in my household bugged me.  I forgive DRM, as most people do, for the convenience offered by the kindle (a devil's bargain).  

So, back to the dim lightbulb.  Apple's ebook DRM is the same as its application DRM and movie DRM, that is, you can authorize the content on 5 devices.  

Books downloaded from the iBookstore can be placed on up to five computers you own that you’ve authorized with your iTunes Store account. You can sync your books to any iPads you own. Audiobooks and ePub files you've added to iTunes will appear in Books under Library. To sync Books to your iPad, connect it to your computer using the cable it came with. In iTunes, select iPad under Devices, then click the Books tab. Choose the books you would like to read on iPad then press Sync. Books will sync to iPad even if iBooks is not installed; to read synced books, download iBooks from the App Store.

http://support.apple.com/kb/HT4059

I still love the Kindle and for pure reading it surpasses the iPad, but this slightly less restriced level of sharing with Apple is making me think twice.  Or at least making me think about WHERE I buy a book before I buy it.