Wireless network profiles

[Graham White]

Just installed Ubuntu, and it works like a dream (even the Centrino
wireless with ndiswrapper). Congratulations. 

Here's the question. I use two wireless networks: one at work
(no WEP key, no need to specify ESSID or channel) and one at home
(shared WEP key, ESSID and channel must be specified). Is it possible
to have two profiles, one for each? Preliminary experiments suggest
that this doesn't work (i.e. that changes made have global,
cross-profile effect). 

Thanks
Graham White