It takes me some time to find it on net, eventually got it from the Linksys forum.
http://forums.linksys.com/linksys/board/message?board.id=Wireless_Adapters&message.id=2371
You can download the driver directly from here.
Still figuring out how to get it working on my RH FC8 partition, tried the rt2570 driver but seems can't get it working yet. If anybody tried it before, feel free to leave a message here :)