USB Wifi adapter recommendation for long range link?

[Marco Walther <marco@sonic.net>]

[ I'm currently not subscribed to this list, so please kindly include me 
in replies! ]

I'm trying to find a good USB Wifi adapter for a [mobile;-)] long range 
point to point link for an ARM based Linux board. Long range in my 
application would preferably be > 30km;-)

I was almost buying the the Ubiquity SR71-USB, it seemed to be the best 
fit I could find. But then I found, that the Linux driver (carl9170) 
still lists the missing long range support:-( So now I'm somewhat lost:-(

That's why I would like to ask for advise;-) My requirements:

* Long range support, preferably > 30km with antenna[s]
* Linux on ARM, no ndis or other x86-only stuff
* preferably small/light
* USB
* still buy-able;-)
* 802.11g would probably be fast enough

So who can help me;-)

Thanks in advance,
-- Marco