Using Knoppix 5.1.1 DVD installation.

su -
wpa_passphrase SSID TextPassphrase

Result is a hex passphrase.

Create /etc/wpa_supplicant.conf :

ctrl_interface=/var/run/wpa_supplicant
ctrl_interface_group=0
eapol_version=1
ap_scan=2
fast_reauth=1

network={
ssid=”SSID”
proto=WPA
key_mgmt=WPA_PSK
pairwise=TKIP
group=TKIP
psk=HexPassphrase
}

To start wpa:

wpa_supplicant -D wext -c wpa_supplicant.conf -i eth2

To get IP info:

pump -i eth2