Possible to connect an arduino to two wireless networks at once?

I need to connect to two wireless networks simultaneously. Would this be easy (and/or possible) with an arduino setup? One of the networks is ad-hoc and the other is infrastructure if that makes a difference. One network is for internal data transfer between devices and the other is to transfer data off-site using an existing wireless network.

--Edit-- I guess I am asking if the arduino is capable of using two wifi shields and provided software libraries can detect and utilize both shields.