Last night I bought a line 6 49 key midi keyboard that was made for mobile devices. It even comes with a plug for the iPad/iPhone 30 pin plug. It's completely powered by the iPad so no need to plug into the wall anywhere. Nice feature I thought. It doesn't have extras like drum pads sliders or knobs, only mod wheel and pitch wheel. It does have jacks on the back for a sustain pedal, expression peddle and USB to use it for a computer as well. It worked really good I thought. As soon as you plug it in it works. No downloading, no drivers. Sustain works great. It does come in a 25 key version if you want something even more portable. I thought about getting that as well down the road for if I go sit at the beach or park or something. But for around the house and what not the 49 sits great on the table, bed or in my lap. Not sure what the 25 is but the 49 was 149.99 at guitar center. Hope this helps you out.