I know you already have this solved, but this is the page I referenced and I know that wpa_supplicant will scan and attach to various APs:
http://www.vollink.com/gary/deb_wifi.html - Nate >> -- Wireless | Amateur Radio Station N0NB | Successfully Microsoft Amateur radio exams; ham radio; Linux info @ | free since January 1998. http://www.qsl.net/n0nb/ | "Debian, the choice of My Kawasaki KZ-650 SR @ | a GNU generation!" http://www.networksplus.net/n0nb/ | http://www.debian.org -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]