WeaKnees.com is now offering a pre-formatted 160GB HDD upgrade for the AppleTV. While the tech savvy can do this with some elbow grease, the plug-and-play compatibility is very attractive to me. I'd much rather spend a few extra bucks than spend several hours copying and formatting hard drives. Call me crazy.
WeaKnees has a special place in my heart. They also have a couple of components in my TiVo.