I attached these two to my Samsung Galaxy S2, which has just over 3,300 tracks of music recorded at 192Kbps and I tried them out with several types of music and to say the least I'm very impressed with the great sound quality that I got from them with everything from Rock to Ballads & Acoustic to Synthesizer stuff from Jean Michel Jarre & Vangelis it all sounds really great, with a nice bass sound when they are fully extended to a slightly more treble sound when squashed closed.
If the volume is a tad low, just a reminder there is a small volume control on the side of it, there also appears to be the possibility to attach a small split ring & small leash type carrying handle, also when you open the packet, don't miss the small fabric carrying/protection bag stuck away in there too (I did & nearly threw them away!).
Don't expect super Hi-Fi quality from them, but they are really good.
They come with a cable which allows for charging from either a USB port on your PC or from a wall USB charger.
For reference the USB cable type is type A to Mini B, should you want to buy a bit more robust charging cable.
All in all I would recommend these small but quite powerful for their size speakers.