From one of the stickys (Most Complete Card Driver Chipset List), in the Newbie Area subforum, I found a link to the Linux Wireless LAN support. On that web page, here is what I found about your card:
Besides that, there are some tutorials for cracking WEP using the Aircrack suite. You can find them in the Tutorials subforum. Good luck!802.11g WPC54GS man: 14e4 dev: 4318 Cardbus Broadcom Bcm43xx green ; Firmware is needed for this chip
[EDIT] I also found this link, hxxp://backtrack.offensive-security.com/index.php?title=HCL:Wireless , but it doesn't show your exact card. It shows the Linksys WPC54G v3 though.