The first looks like this:
I had this one with me during my trip to Vegas for the WSOP. When Carlos final tabled one of the Aria daily tournaments, we were on the rail for twelve hours. My Galaxy S3 didn't last that long on one charge, given all the texting and tweetng of his updates. But this stick, which is small enough to fit in your pocket (it is the size of a classic Bic cigarette lighter), helped me get through the event. It easily plugged into my phone and restored an almost full charge. It will typically fully charge my phone if I charge while the phone is off or idle. It will provide mostly a full charge when I charge while using the phone.
My other charger, also a charity dinner gift, is more versatile.
This version charges faster, and has a greater capacity. We put it to work on the beach during a recent vacation. With the wife's iphone 4s synched to a bluetooth speaker, we were the annoying Americans playing our music on the beach (actually, we were quite discreet). When the phone dropped below 10%, we connected to this charger. We continued to play the music and run bluetooth, and the device provided a full charge. This has a larger shape, kind of like a small cell phone itself, but it is very light and thin.
If you depend on your phone for just about everything when you travel, a cheap, portable batter stick is a great addition to your travel gear.