By Fred T:
Over the years I've tried almost every tweak in the book, and I finally concluded that most of the commercially available tweaks have much in common with the weight loss products found in early morning infomercials. They work, but only if you believe they work.
In spite of this disappointing experience I've found a few affordable under-$100 tweaks that make an immediate and noticeable difference. I prepared a summary, and you can find it here:
http://fredt300b.smugmug.com/Hobbies...5835&k=nmMQbw3