Years ago I had a palm iiix (my first palm PDA). I really loved that device. When I found out that there were possibilities to make music with a device that small, I was astounded. My first departure into handheld music was buying Minimusic software and an SG20 module for my palm IIIx.
Wow, that was fantastic. A full MIDI sequencer in the palm on my hand. For some time I thought that was the best that there could be.