For the budding musician in you, if that budding musician is extremely ambitious, Akai has made the SynthStation49 iPhone and iPad dock.
Not one of the smaller docks, this is a full-fledged, 49-key velocity-sensitive keyboard. It even has manual pitch control and drum pads. It’s also the follow-up to a previous SynthStation dock, which was much smaller and less, shall we say, professionally done.
My guess is that synching a keyboard painlessly to your iPad has musical recording advantages, in the form of apps, since it’s iOS CoreMIDI compatible. There’s direct in-app MIDI recording, output through ¼” jacks, and if your iPad isn’t handy, you can use the SynthStation49 as a USB MIDI controller.
Having not yet been approved by Apple, pricing details are not available.