Obligatory, "the best security is awareness".
So I manage a hotel across from a strip club, and every thursday they do a live radio broadcast from one of the local stations. Needless to say at times it gets a little rowdy and some people drunkenly stumble into my lot to pee on cars, and make general nuisances of themselves. Sometimes they park in my lot, despite the clearly posted signs saying you will get towed. Most of the time, asking politely for them to leave gets them to leave. Other times, not so much. And its for those times that I feel I need something thats a little more imposing than a stern warning and a call to the police (the problem being that often times the police are slow to get to this part of town).
First off, no guns. Too much potential for things to get out of hand way to quickly and I don't want that on my or my employees heads. Push come to shove, I'd rather have a window broken and have to deal with the situation that would come from a gun. Other than that, I was thinking some form of stun gun, but I have no idea of what I'm dealing with.
At the most I'm looking to spend maybe 700 on it, with some leeway. But other than that, I'm open to suggestions.