If you want to continuous watch on your IP address and your browser is firefox, here is the best way to retrieve your IP address.
You just need to add Live IP Address
add-ons to firefox browser than restart your browser. You will find your internet IP address in your firefox browser. It will display in the firefox status bar.
IP address will automatically update after every 16 minutes in the status bar, if you want to change the interval of IP updation, you can choose the value between 17 to 1422 minutes. You can also update it by right click on the IP address by choosing “Force Update Now”.