Here is my latest DIY project, a MIDI Switcher. It has 25 MIDI ports and 44 switches to help manage the MIDI traffic of my 11 MIDI units. I wasn't comfortable trying to wire up an IC based switcher so I opted for this much simpler design. It is not too elegant but it gets the job done. It was a fun project though I had a bit of trouble stuffing all of those wires inside :-) .