See
http://www.fsf.org/resources/hw/index_html/net/wireless/index_html/cards.html
The Wireless-g version of your USB adapter (WG111) works in fully-free
systems with the ath9k driver. And there are plenty of other USB adapters
from that list. Amazon.com is a good place to look for them. But the WN111
may have an entirely different chipset. If your adapter lights up, it may
only indicate that a USB connection is working.
I wish wireless adapter technology would become more standardized by now,
like keyboards and mice are. That would help fully-free systems a lot...
