Ye' old general discussion board. Basically, for everything that isn't covered elsewhere. Come here to shoot the breeze, shoot your mouth off, or whatever suits your fancy. This forum is not for asking programming related questions.
Would not be hard to write, as it sounds much like some sort of the old bannerswapping-services. If there are such services offered on the net, I don't know.
Post it in the forums "Project Help Wanted / Volunteer Work" part. Perhaps you'll get lucky and get someone to make it for you.