Messing with boot ROMs is a painful pile of headaches that nobody wants to pick up. But it'd be nice to swap the Nook Color's software for something more versatile - say, Android 2.3. Just pop in this MicroSD card.
Once installed, the Nook2Android will let you dual boot, choosing between the default Nook colour package and full-fledged Gingerbread. This is great, because as nice as the Nook is, it's also a very tasty piece of hardware, and using it with software not pegged sharply for reading would be a treat. And if you want your Nook bac to the way it was out of the box, just pull out the card - no permanent changes, and no voided warranty.
The setup process is a little involved, but much, much easier than trying to futz around with custom ROMs on your own. A 32GB boot card will run you $US90, with an 8GB variety costing only $US35. [Nook2Android via Engadget]