I've just bought this speakers today before doing any research. Was intentinally wanted to buy a smaller set from Sony Ericsson to use as my traveling speakers for my coming holiday. The shop's salesperson recomended this set and let me try on spot with my K750i handphone, and I must say it's really out of my expectation.
I'm a buyer for my company PC accessories, have bought many pairs or larger PC desktop speakers ranged from 2.0 / 2.1 to 7.1, and found that this small little chic can even out perform some bigger size 2.0 desktop speakers. The clarity is very good, only except the bass which you shouldn't expect it the same from a sub woofer, and I've heard a lot of worse 2.1 speakers.
It doesn't come with any power adapter but you can easily buy any conventional 5w adapter with the correct polarity. This cute little set is lying at my baby's room while I'm not travelling, it's really made both of us sleep faster with the sweet sound, which is even better than my wireless speakers from Pioneer Home theatre system.