Daffodil UMC120 12-24V Mini USB Car Power Adaptor/Charger with 5V Voltage and 800mA Current Output
Bought this to keep my phone and headset charged, and it works perfectly. It puts out enough juice to charge the most power hungry phones, but it does get warm. It doesn't get hot though, so I'm not complaining. It has a nice low profile, so it looks like a regular lighter to most people. Or at least it would, if it didn't always have an LED on, even when nothing is plugged into it. That's my only gripe, but it's a very minor one.