I use the same type for my GZone phone and it also came with a mini-usb tip that charges my mp3 player. It works really well except when I charge I can't use the MP3 Players FM radio *shrug*.

If you buy them in a store just make sure it comes with all the tips it says on the package before you leave the aisle. I had to go through a few stores till I found one that didn't have all the tips ransacked from all the packages. It was nice that they stick them out the back so you could try the tip but either people stole them for fun or so they would only have to buy one package to charge different devices.