Amazon offers a 30-day trial of Amazon Prime for free. Better, yet when you purchase a 1-year subscription at the end of that trial, you'll receive a $10 Amazon Gift Card for free. (Prime membership costs $79 per year.) That's the best such additional offer we've seen with a Prime membership, which features unlimited 2-day shipping for free, no minimum order size, unlimited Instant Video streaming, and one free borrowed book per month from the Kindle Owners' Lending Library. Deal ends August 25.