A little off-topic, but is anyone else irritated by the fact that many websites redirect you to their homepage when you access the desktop version of the site from a mobile device, and vice versa? I don't understand why you would ever implement this sort of behavior.

If I were to put my "suit-hat" on, I'd think like this:

"Most of the population that encounter this inconvenience will think 'oh, I navigated to the wrong version of the page, my mistake. Now, time to find the proper page'. They aren't going to realize that we could have implemented the logic to properly route the reader to the corresponding page on the other version, mobile or desktop. Furthermore, while I can't quantify how many people get pissed off and become resentful of the site for implementing this kind of behavior, I can quantify how many more pageviews we get from putting up this inconvenience (via logs). I can translate this increased pageview to increased ad revenue (simple multiplication). That means increased (at least superficial) profits! I better get a promotion next quarter!"

(I admit to employing excessive hyperbole, but I wouldn't be surprised if people actually thought like this)

The correct behavior would need them to write some logic (even if it's just: s/mobile\.//) to point to the correct desktop URL based on the mobile site URL, and then maintain this logic in future. That's extra work!