Hardware Modification Prerequisites
At the moment, some of the hacks floating around will require opening the Apple TV unit. Doing so will permanently void your warranty; please keep this in mind.
You may now boot the Apple TV version of Mac OS X from an external USB hard drive, which does not require opening the box. It is doubtful this simple act voids the warranty, but if you load some patch or software that damages the product you will likely have to fix it yourself.
Some of the items you may require for AwkwardTV mods:
* Apple TV * Torx set (specifically #8,#10) * USB drive enclosure 44pin, 2.5inch * Storage to hold backup image of original drive * Backup program (dd for example) * Anti-Static Wrist-strap or related (to be safe) * Electricity / TV * HDMI to DVI converter cable * Intel Mac OS 10.4.7-8 (if you want to add OSX components)