Twitter Bot -- Already Exists?

Alright, i'm in need of a very particular Twitter bot. I want to monitor various hash tags, and whenever they're mentioned with a link, I want to log that link as well as what hash tag was used.

Does anyone know if something like this already exists? If so, where can I find the software?

If not, shoot me a PM if you'd find this useful, and i'll keep you updated as I develop it.