Still not sure ...
To clarify (I think
) Looking for a small(ish) wireless router that will operate (from a power standard) both in North America, Europe, and Asia.
Size and weight are both important. Looking to have one or two computers connected.
Unfortunately, I can't help much with the question as stated. It will be interesting to see what other responses you get.
I'm not aware of any "standard" wireless router that is made or designed especially for portability. By this I mean a wireless router which connects its wireless clients to a larger WAN (usually the Internet) via NAT. The WAN port I'm familiar with is always ethernet using an RJ45 connector.
I believe most (all?) manufacturers of the smaller devices are targeting usage within either a home or a SOHO. As such, size and weight are viewed more as a cosmetic concern. A way to possibly distinguish the product in a minor way from others on the market.
I think most people buying are more interested in some combination of feature set and price with size and weight a much lower concern. After all, the typical router is already not that big a box. And if that box is most likely going to be "hidden away" in a closet, back room, top shelf, or whatever, then how much does size and weight matter?
About the best I could do is to suggest looking at the routers which use internal antennas. As for portability of the adapter, if you travel as much as your question implies, then you probably already know much more about power adapters/converters for various countries than I expect I ever will.
You might also look into trying to connect your computers via an "ad hoc" wireless network. It's a feature I've seen listed on some of USB wireless client adapters. How useful it is in general or in your specific case I couldn't say since I've never actually worked with it.
What I
have seen sold particularly for people who travel are routers that allow multiple wireless clients to connect to the Internet via a cell phone data line. I remember seeing a review for a gadget like this in David Pogue's column.
Here are some links to Pogue columns from a quicko search. I don't think this is what you are looking for though.
Wi-Fi to Go: The Hot Spot in a Box
Wi-Fi to Go, No Cafe Needed
But then again, I'm still not really sure what it is you're looking for or, more importantly, what "problem" you are trying to solve with it.
-irrational john