This project was created of an evening with the intent to make it easy to watch pastebin for a given keyword and cache the result. It's written in python and designed to be easily used as a module. With very little work you should be able to import a function from pastegrep, pass it an expression you want to watch for, and optionally give it a function to call whenever it finds a paste that matches your regular expression.
Examples:
./pastegrep.py password
./pastegrep.py @gmail.com @yahoo.com anon password