> but a DVD player bought for your TV, How do you hack that?
 
There are different ways, depending on the player.  Some you can "hack" by pressing a sequence on your remote (like a video game easter egg), some require a firmware upgrade which can be flashed (ie put it on a CDrom and put that in your player), some require a whole new chip.
 
See here: http://www.videohelp.com/dvdhacks
 
and some might show up here that aren't listed in the above:
http://www.videohelp.com/dvdplayers
 
My standard DVD player requires a new chip for region free so I went out and bought a cheapo player for under $100 that allowed a firmware upgrade.
 
The only way you can "screw yourself" is if something goes wrong with the flash upgrade -- like a power surge, etc.  Flashing and remote sequences are almost always reversible (and I say "almost" because there might be one that isn't but I've never read about one).  Obviously replacing the chip is permanent.
 
-paul