PricePlunge offers the Eton BoostTurbine 1,000mAh Hand-Powered Battery Pack, model no. NBOTO1000B, for $14.99 plus $1.99 for shipping. That's a buck under our May mention and the lowest total price we've seen. (It's a current low by $27.) This battery backup features a standard USB port and a hand crank. One minute of hand cranking purportedly produces enough power for about four minutes of talk time.