I've noticed in edgy that network-manager-gnome doesn't play well, it'll show the networks in range, and it'll attempt to connect.. but it won't actually connect, and where wpa networks are listed it'll ask for a psk, but it still doesn't do anything.

However, I can connect manually using iwconfig, including using wpa, this guide i found particular useful:

http://www.vollink.com/gary/deb_wifi.html

(although i skipped the part on ifplugd and messing with /etc/network/interfaces)