While all the other options will work, if you need to get your IP address that often, I would have a dedicated program running just to deliver it to you.For instance, I use a desktop gadget that displays my IP address.
This one, for instance, will display your IP address:http://pcsupport.about.com/od/toolsofthetrade/gr/system-monitor-gadget.htm
I also know there has to be a program somewhere that will sit in your system tray and feed you your ip address whenever you click on it.
Or maybe you could use a firefox/chrome extension.
Hundreds of ways this could be done. Just use your imagination.