Thanks for your thoughts on the matter, but it has happend to me. The offer was retracted based on lack of interest on my part as seen by the company - this is back in '07 when I was in talks with a few companies and most had given me offer letters.
You need to be careful with your advice to others, I know you mean well but it could really mess somebody up in a very real way.
I actually use a small tweak: rather than "all are equally good so I'm choosing based on salary," I pick the company I want, then go to the others and say "another company has offered me X. Could you offer me a little more?" Once they do, I go back to the company I want and say "another company has offered me Y. I really want to work for you, so could you match Y?" Perhaps the "I really want to you," and only asking to match another offer, is more important than I thought?
The best thing is to get the company excited about you. They get excited by knowing that a) you're awesome in your skills, b) you're gonna be easy to coach, c) you're gonna hit the ground running, and d) you're passionate about the company because you buy into the culture and mission.
My advice: go to salary.com and such sites and look at that data for that job, and tell them you are in the 80th, or 85th or 90th percentile, and why (what a typical guy in your fild does not know or what makes you exceptional).
You need to be careful with your advice to others, I know you mean well but it could really mess somebody up in a very real way.