LPK25 portable piano
When on vacation, I saw someone playing a ukulele, and remember someone saying how handy that is, and that there should be an alternative for a piano. At home, I have a very small LPK-25 keyboard, but it connects to a computer over USB and acts as a MIDI device. The idea is to have a battery and a raspberry pi with synthesizers on it, and have some loudspeakers and a 3.5mm jack, so as to make a portable synthesizer.