Hey guys looking for a programmer, I wrote something a while ago that could fit the trick.
The basic concept is that every 5 minutes I grab the rss of my search topic (the name of a US city in this case) and parse it for the user information, use the API to post a retweet (can be any message I want...) @ that user. It could be modified for multiple accounts, custom messages, etc...Message me if anyone is interested, I've been meaning to expand it and was thinking of providing it to the general public....message me if you're interested...
BTW, my bot has been running for just about one year, and has 38k tweets, 1337 followers (lol...) and has yet to be banned...simple little toy to see if I could do it...