If you do forget the address of your pi, you may be interested into Senti§nel.
Senti§nel will tweet your IP, and if you follow the step-by-step configuration, it will be done every time the pi boots.
Using it, you will only have to remember the name of your twitter account (*), which never changes
You can see more about this project here : https://bitbucket.org/0xAvier/senti-p-nel/overview.
You can download it there : https://bitbucket.org/0xAvier/senti-p-nel/downloads/.
The all installation takes ~20 minutes. Less if you are familiar with creating Twitter bot, and installation process on unix.
Feel free to ask / post any answer / question,
(*) You may want to create a new account dedicated to that