The team at Teenage Engineering has created a stylish looking portable synthesizer but it will cost you. It has a hefty price of $1,100 and it's such in high demand that they're currently sold out. The OP-1 synthesizer was created to be the world's preeminent, portable synthesizer. It merges the best of classic, analogue soul with the latest in digital technology. It's more like a hybrid of sorts with a digital synthesizer and MIDI controller with tons of features.
It has 8 synthesizer models (FM, Virtual Analog, String, +), 8 samplers, on board effects, OLED display, battery powered, built in microphone, FM radio, built in speaker, mp3 export, and some really unique sequencer to explore.
More info here: http://aiaiai.dk/store/things/op-1
See Youtube videos on the OP-1 here: http://www.youtube.com/user/teenageengineering