As someone who does a lot of travelling around the country, I find it very useful to have a set of portable speakers that can be plugged into my MP3 player so as to listen to music without headphones. Unfortunately the sound quality you get from most portable speakers is very poor with the bass in particular, failing to impress.
When I ordered my x-mini, I did so because of the size and design rather than any expectation of performance. However, these portable speakers are a very impressive piece of kit, so impressive in fact that as soon as I had seen my first one in action, I went straight online to buy a second.
The speakers are powered by an internal battery which can be charged through an included usb cable. The sound quality is so good that I use my speakers as replacement for my laptops speakers when listening to music and thus running low on charge hasn't been a problem for me so I can't comment on battery life further than what the official statement has to say. The sound quality as stated before is very good, the speakers can't quite cope flawlessly with the loudest parts of some songs when everything is turned up to full volume, but I think to expect that may be unrealistic for a portable speaker in this price range. Even saying that the volume these guys can produce without any distortion is amazing. The bass is far superior to any of the other portables I've used and the size is perfect for just throwing in a bag when you're on the road. There is also a system in place which means you can "buddy jack" numerous x-mini's thus further increasing their sound output. All the equipment required for this, as well as charging comes included so you don't need to worry about buying extra cables or peripherals.
All in all these are a great purchase and I've already recommended them to some friends. They should be seriously considered if you're looking to invest in some portables. I honestly think they would be cheap at twice the price.