I'd have to second the OP's idea, as it does have merit. Hopefully the work on getting the USB Host working can show some results in the future....
However, I'm in the same boat, where I have a Nook Color running CM7 I use as a tablet, and an N1. I'm also on business in China a lot, and I prefer to use the NC in place of a laptop, although in some places wireless is flakey or non-existent. In those scenarios I'd rather not use the N1 as an access point using the 3G network to run data, as it adds up quick, even when using China sim cards.
It's these situations where a means to connect an android device to a physical ethernet is desirable, whether by USB or by wireless to a dongle.
This is the one device I'm testing out now is a CQR-980 from Cnet. You'll have to google it, because I can't post links.
The reason for this unit is it's size (its 3.52 (L) x 2.32 (W) x 1.06 (H) inches), and full support for setting up a secure wireless environment. If it works right, I will pre-configure it as an access point with WPA2, and it should be able to be plugged into any ethernet port in a hotel or otherwise, and I should get an IP on the NC or N1 via wireless.
If anyone else has found a better way to make this sort of setup work, would love to hear of it. The fewer devices I have to bring the better. Yet this is still better than dragging even a small laptop around.