Nitrous has become much safer in recent years. The safest route to run (generally) is a wet shot, which is more expensive, but most people say there is less likely of a chance for your car to lean out. A wet kit injects gasoline and nitrous into the intake together, whereas a dry kit injects just nitrous, and the computer is boosted to produce more fuel through the injectors.
I'm seriously considering nitrous for my car. A wet kit, with all the goodies, no installationg and tuning, runs 1k or so. Would I rather have a blower? Hell yes. But nitrous is a pretty damn good substitute.