Probably one of the most used tools on the web is "what is my IP" tool. And this website is just another one of those. But it is not totally useless, because it offers few neat features:
This page displays only your IP address in plain format with no padding. Simple as it sounds, trivial to make, still very useful if you have another program or script that wants to find out it's own IP address. In past I had to do this by parsing HTML of some other "what is my IP" site, while hoping, owner will not make any changes to his webpage, so my parsing part of program keeps working.
Second cool feature of this website is email updates on IP address change. This works the
following way:
Once you have registered your email address you will obtain secret token. Then
keep sending the token back to this site regularly and once your IP address changes this site will notice
and notify you via email message.
I hope this website will have some use for you.