Sony h.ear go is a wireless mobile speaker in their multi-room line that you can take with you and play music on the go. You stream music to it through Google Cast, Spotify Connect and Bluetooth. It also has a line in for old school connections. It outputs 12W+12W. The battery lasts up to 12 hours and it even supports high resolution audio, even though it may be on the small side for you to actually hear the difference. So have it at home as part of you ordinary multi-room setup and bring it with you on your trips. A great addition to the Sony lineup.
Oh, and it comes in lime, pink, blue, red and black. The price is 199$.