There is another great audio tool called "Sound Forge" which I highly recommend. It takes a ton of CPU to use but has lots of great features.
I use it to clean up old LPs I've converted to audio CDs.
Here's more info:
Sony Media Software - Sound Forge 8 and Sound Forge Audio Studio
You can find this one the internet pretty cheap if you look hard enough
"It's funny the way most people love the dead. Once you are dead, you are made for life." - Jimi Hendrix