OP-1

This sounds almost too good to be true. The new OP-1 (Operator1) by Teenage Engineering is a pocket sized MIDI controller and a stand alone synthesizer with 8 adjustable models, a sampler/sequencer with on board effects, has a built in microphone and speaker, an FM radio with the capacity to sample (hello Exile), it's battery powered and has MP3 export capabilities to email your final product.
Sounds pretty unbelievable, but looks like it's real and coming sometime this year... (price TBA)

OP-1 stands for Operator 1 and is a pocket size controller for your favorite software sequencer. Connect it to your laptop and it lets you control your sequencers transport with the common play, stop, rec, forward and rewind. Use it to control your software synthesizers with the 4 rotary encoders and 16 dedicated quick keys for fast selections.

When you disconnect the OP-1 from your computer you suddenly have a stand-alone portable wonder-machine with 8 synthesizer models, 8 samplers and effects like Delay, Flutter, Filters and EQ all built in. Use all that synthesizer power to record your work with the truly unique (at present time, secret) sequencer. We promise you a really cool and creative way to record your sounds and tweak them in a completely new way.

Use the magic step sequencer/arpeggiator to get the notes right. If that is not enough use the built in motion sensor that sense every shake or move you make and turn it into really cool sounds.
Then relax and sample a beat from the built-in FM radio or memorize a tune by whistle it into the built-in microphone. Play your piece to your friends through the built-in speaker. Or...convert it right away to mp3 and mail it to them.