To scan your eth1 network interface for the details of available wireless networks, run the following...
iwlist eth1 scan
Should give you an output something like this:
eth1 Scan completed :
Cell 01 - Address: 00:14:7F:40:20:4A
ESSID:"SpeedTouch6A2A8C"
Protocol:IEEE 802.11bg
Mode:Master
Channel:1
Encryption key:on
Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 6 Mb/s; 9 Mb/s
11 Mb/s; 12 Mb/s; 18 Mb/s; 24 Mb/s; 36 Mb/s
48 Mb/s; 54 Mb/s
Quality=64/100 Signal level=-62 dBm
Extra: Last beacon: 6550ms ago
Cell 02 - Address: 00:11:09:0C:4F:D7
ESSID:"LUFC"
Protocol:IEEE 802.11bg
Mode:Master
Channel:11
Encryption key:on
Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 9 Mb/s; 11 Mb/s
6 Mb/s; 12 Mb/s; 18 Mb/s; 24 Mb/s; 36 Mb/s
48 Mb/s; 54 Mb/s
Quality=39/100 Signal level=-77 dBm
IE: WPA Version 1
Group Cipher : TKIP
Pairwise Ciphers (1) : TKIP
Authentication Suites (1) : PSK
IE: IEEE 802.11i/WPA2 Version 1
Group Cipher : TKIP
Pairwise Ciphers (1) : CCMP
Authentication Suites (1) : PSK
Extra: Last beacon: 6360ms ago
Cell 03 - Address: 00:18:4D:40:22:32
ESSID:"NETGEAR"
Protocol:IEEE 802.11bg
Mode:Master
Channel:11
Encryption key:off
Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 6 Mb/s; 9 Mb/s
11 Mb/s; 12 Mb/s; 18 Mb/s; 22 Mb/s; 24 Mb/s
36 Mb/s; 48 Mb/s; 54 Mb/s
Quality=51/100 Signal level=-70 dBm
Extra: Last beacon: 6350ms ago
Cell 04 - Address: 00:A0:C5:DB:5E:4D
ESSID:"whisper"
Protocol:IEEE 802.11bg
Mode:Master
Channel:1
Encryption key:on
Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 6 Mb/s; 9 Mb/s
11 Mb/s; 12 Mb/s; 18 Mb/s; 22 Mb/s; 24 Mb/s
36 Mb/s; 48 Mb/s; 54 Mb/s
Quality=86/100 Signal level=-43 dBm
IE: WPA Version 1
Group Cipher : TKIP
Pairwise Ciphers (1) : TKIP
Authentication Suites (1) : PSK
Extra: Last beacon: 160ms ago
