Thanks for the info guys. About the flushing, what my mechanic basically did was take out the engine and soak it with this chemical (I'll get the name of it from him tomorrow) and then put the engine back in the next day. Then for two weeks he would drive it home at night, soak it with the engine still in the car overnight and then drive the car back to the shop the next day. This, he said helped get all that carbon out of the engine. Now what you have to understand is that my car just rolled over 241,500 miles today. So it really, really needed this done. The difference is phenomal. When I took it to him, the car took (I'm not kidding) 30 seconds to accelerate to 30mph. It was horrible. Now I'm smoking Mustangs again.
The mechanic does not have a website. He works in a small-town shop and has been working on our cars for 15 years. He's the man!