Does anyone know of a good fire-retardant paint for brick fireplaces?

have you checked somewhere like Lowe's or Home Depot? I remember seeing something that was made for that type of thing, but I can't remember the name or brand off the top of my head.

I'm not sure how serious of a product you are looking for but here are a couple links to some good quality fire retardant paints:
http://painttoprotect.com/
http://www.fireretardantsinc.com/
http://www.contegointernational.com/