Determine your home router's IP address remotely

Today I needed to determine the public IP address that my home network was using but I was not physically located at home and didn't have a means of remote access into my network without the IP address. (I'm working on getting dynamic DNS and remote access and all that but it isn't up yet.)

So, I thought really hard about what I could do and it came to me...

I happened to know that there was a computer on my home network with a browser window opened to Gmail...So I logged into Gmail from my remote location and scrolled all the way down. In the bottom right hand corner, this was displayed:

I clicked "Details" and there was my home IP! This saved my bacon!