I just picked up a midi converter for my bass.
Technology is just amazing, I run it through my midi keyboard/ controller into the computer and I can write sheet music as I play, even control the keyboard (play keyboard sounds) with my bass.
It is monotonal ( one note at a time) so sometimes I have to go into the music and add notes but for the bass it works pretty well.
I just got it so, still playing with it. I'm kind of stoked though.