You can lookup a Polycom VVX phone's IP address by clicking the button with a house on it and then choosing the following options. Settings -> Status (option 4) -> Network (option 2) -> TCP/IP Parameters (option 1) and this is where you can see your IP address. 

There is a faster method. You can press and hold down the 1, 4 & & keys simultaneously to get the phone's IP address.