Comment Dumb-asses! (Fry's is not so dumb...) (Score 5, Informative) 287
Fry's has a simple system for this.
1. You tell the sales associate (it's not done at the checkout counter) what site you want them to match.
2. They check it against the list of sites that they are willing to match.
3. They go to the site on their computer, and look it up.
4. They print an invoice that you take to the counter with your purchase.
5. BTW, they have incentive to do this, because they get something any time they print an invoice. I don't know the details, but it would be dumb for Fry's to withhold whatever the reward is just because it was a price match. So, anytime somebody at Fry's is actually helpful (rare, I know, but sometimes happens...) don't balk when they want to print an invoice!
You don't get away with just showing them your screen.
You can show them a screen, from the web or some price-search app, and then they will go to their own browser to look it up.