I tried a USB webcam and a external USB sound card, and neither worked. Likely it's a problem with kernel drivers. Luckily thumb drive support seems to be built in and we just needed to "activate" it.
I actually considered a Nook Color several times, as its got a nice screen. But a 7 inch device is not what I want in a tablet - it's just too small a screen.
No USB host mode on the NC, I assume? If the kernel supports, I suppose the the ramdisk and vold config could be altered for thumb drive support.
Thank you, roebeet. Kernel support of USB Host is in the hands of CM7 devs for NC, but hopefully there are some applicable generic stanzas to utilize in our case. Naturally, plus your altered ramdisk and vold configs. USB cam could be splendid addition here, too.
As for 7" form factor, it's perfectly fine with its 169 dpi and portability/pocketability. My next tablet will be RIM BB Playbook with similar display, and I'm inclined to see ~10" screens more in netbooks. But it's just me who still likes his WPDN.