performance chips

I've been hearing alot about theese preformance chips lately, and I've considered buying them- but one of my friends said that they are bad for the engine. I mean the engines are governed by the stock computers so that they wont reach as high of rpm's and thus last longer right? Will a chip significantly wear down my engine/transmission? Would it be a better idea just to buy a K&N air filter and some headers to unlock horsepower without hurting the engine?

I've had a Hypertech in my truck since the day I bought it. It hasn't had any negative effects on it in any way (besides the mileage w/ my heavy right foot). I've had the rev limiter set up to 6000, the speed governor is at 128, etc...
I'm selling it and investing that money in a custom tune for even more power!

how many miles do you have on your truck?

I've had the Hypertech Street Runner in my '92 for the past 80,000 miles. It's got 197,000 miles total, plus I raced it in mud drags for 5 years. It still runs fine but I am planning on rebuilding it soon, mainly because it's burning oil now, but with almost 200,000 mi., I'm not complaining. I think if the chip would have caused any problems, it would have happened about 3 years ago.

Thanks for the input guys...anyone else? Anybody have a bad experience with a preformance chip?