Last weekend at CompUSA, I bought a Netgear Wireless Travel Router, for $59.99 with a $50 rebate from Netgear -- really nice for less than ten dollars.

The Travel Router is actually described in the company's literature as the size of a deck of cards, and that's its size; it's also advertised for use in hotels and conference rooms and such where there's just one Ethernet connection. (You can set it to accept only one user or multiple users with a switch on the device.)

This sounds like what you were looking for. I've used it a couple times so far and it works fine. Can't say what its range is, however; I never walked more than a few feet away from it.

Edited to add: Here's the post where I mentioned it previously:

http://www.internettablettalk.com/fo...&postcount=255