There are a few things that change depending on which network I'm on. /etc/hosts, my unison config (because it seems to ignore /etc/hosts and go straight to DNS), and some extra things I use in /etc/pcmcia/wireless.opts, the most crucial of which is the WEP key.
To switch configurations, I manually run a script that changes a directory symlink, and each different setup has a directory with the appropriate files. I've seen a bunch of autodetection packages, but as far as I can tell, they all depend on having IP working already, which isn't the case if I haven't picked a WEP key yet. I'm told that MACs are broadcasted in the clear, even when WEP is used, so we ought to be able to sniff the wireless traffic, notice a familiar MAC, and select based on that. Has anyone tried doing that?
