I've recently been playing with the iPhone version of Amplitude and I'm quite impressed with the possibilities.
I've just been thinking how nice it would be if it was possible to plug an Eigenharp to an iPhone (or other smartphone) and have a basic app that could be used to practice. It would make a great practice combo, you plug the Eigenharp to the phone and monitor with headphones or through the internal speakers. I'm pretty sure we're a long way from this, but it would be quite awesome...