The excellent site Lost in Mobile linked to this Mashable piece about alternate ways to organize your mobile app icons. It reminded me of one time when I had some spare mental cycles during a conference and decided to arrange my iPad's icons by ones that had lazy, one-letter based icon design:
I then decided to do a screenful of "icons by face" (then vehicle) - admittedly these were mostly games.
The Website is Down, and it's infamous bit starting at 7:50 -- "You can't arrange them by penis" (Obvioiusly language is a bit NSFW.)
All jokes aside, it's interesting how people use different methods to arrange icons, from the more OCD-ish and orderly (e.g. by name or color), by function, by "muscle memory", or some mix of all of those.
FWIW, here's how I arrange the icons on the device that's by far most important to me, my iPhone. (Lost in Mobile is running a "readers show us your homescreen" series, which is why this is so nerdily annotated. The site's forums are very civil, given how many Android and iPhone fans are onboard there.)