dealing with networks...

# Scan for wifi...
sudo iwlist <interface> scan

# Connecting to open WiFi
sudo iwconfig <interface> essid "<ESSID>"

# Getting IP address...
sudo dhclient <interface>

# Connect to WEP encrypted network...
iwconfig <interface> essid "<ESSID>" key "<KEY>"

OR

iwconfig [interface] mode managed key [WEP key] (128 bit WEP use 26 hex characters, 64 bit WEP uses 10
iwconfig [Interface] essid "[ESSID]" (Specify ESSID for the WLAN)

####

# CONNECT TO UNENCRYPTED NETWORK
sudo ifconfig <interface> down
sudo dhclient -r <interface>
sudo ifconfig <interface> up
sudo iwconfig <interface> essid "ESSID_IN_QUOTES"
sudo iwconfig <interface> mode Managed
sudo dhclient <interface>

# CONNECT TO WEP NETWORK
sudo ifconfig <interface> down
sudo dhclient -r <interface>
sudo ifconfig <interface> up
sudo iwconfig <interface> essid "ESSID_IN_QUOTES"
sudo iwconfig <interface> key HEX_KEY <<<-------- If using ASCII Equivalent, this is s:ASCII_KEY (please make note of the prefix s:)
****Additional Comand that may be needed  -- sudo iwconfig <interface> key open  <<<----See note below
sudo iwconfig <interface> mode Managed
sudo dhclient <interface>

# CONNECT TO WPA NETWORK
http://ubuntuforums.org/showthread.php?t=571188