Cleaning Burned Pots and Pans?
Barkeepers Friend also works amazingly well. Most grocery stores have it in the section where Comet and other cleaning powders are sold. Its non-abrasive and really shines up stainless steel to look like new. I use it on my cooktop and many other things too...
Cleaning Non-Stick Cookware?
I use Barkeepers Friend for the bottom of my pans, and they still look like new. Its a powdered cleanser like Comet, etc., but it is not abrasive at all. You can buy it at Walmart and most grocery stores. Works really well.