We've already run down how to root nearly any Android phone under the sun, but if you haven't bought yours yet, you may want to check out which are the most root friendly. This list will show you.
While rootability isn't one of the most important specs in choosing a phone, you may not feel like going through the trouble of manually rooting your phone (or giving up your root access when updates come out). The fellows over at Unrevoked.com have put together a pretty great list ordering phones by root-friendliness: from devices like the Nexus phones on which rooting is supported, to devices like the Motorola Droid and G1 on which rooting is extremely easy, to devices like the HTC Desire that constantly try to keep you from gaining root access.
As we've said before, nearly any device is rootable if you try hard enough — but if you don't want to go through the trouble, taking a peek at this list before you buy is probably a good idea. Hit the link to check it out.