If you travel often for work and attend conventions, the last thing you'll want is a dead phone, right. If that's a situation you'd love to be able to avoid, you might be interested in checking out one of Hammacher Schlemmer's products; a oxford woven cloth business case with a built-in charger. Yup, the back itself packs a 6,000mAh battery of its own that will be able to charge an iPhone about three times before finally requiring a charge itself (which should take 3.5 hours to fully recharge).
Ubergizmo, This business case will charge your devices while on the go