128 Hex encryption

[Christopher Brown]

Does anyone know (and if you do will you explain) how to set 128bit 
encryption (WEP)? I have a number of wireless devices and a number of 
wireless access points (two of which are not mine) in my area and would 
like a small bit of security so I am using WEP on my router's firewall. 
It works great on the Mac OS side but I am unable to connect to my WLAN 
without setting up my wireless connection under linux. Specifically what 
file(s) do I need to edit and what are the instructions I need to give them?

Thanks,
Christopher