Motorola P793 Universal Portable Power Pack battery charger for a good couple of months now. In fact I rarely leave home without it. It's a slim portable charger that is perfect for any heavy smartphone users like me. Always connected, today's powerful (and inefficient) smartphones demands more than the too-small-for-smartphone batteries that all the phone manufacturers seems to think are enough.
Proporta Ted Baker charging kit, which I tend to only carry with me during weekend excursions.
Motorola DEFY. It outputs at 500mAh, which is decent enough to charge most phones in under two hours.
lowest price I can find on a UK online store), it is a bit pricey for what you get. For the same price you can get a Proporta USB Turbocharger 3400, which has a battery capacity of more than double that of the P793. Having said that, the Motorola P793 is a much more portable and compact charger than the Proporta, and is perfect for people who needs a bit more juice for their smartphone for the day.