I'm coming from the Archos 101 which does have USB host drivers.
I think that USB Host support is probably just a matter of time on the Nook Color. It needs EHCI_omap driver etc. The folks working on the Beagle Board have a similar chipset environment (only the TS chip in the Nook Color is just a catalog version of but similar to the one on the beagle board). I saw a thread where they were doing some tests for USB Host and i think they are having some preliminary success. I think i'm going to press the Easy button on this one and just see when support gets added.
XDA Developers was founded by developers, for developers. It is now a valuable resource for people who want to make the most of their mobile devices, from customizing the look and feel to adding new functionality. Are you a developer?