Played a thing the other day with a nicely minimalist set-up: 2 acoustic-electric guitars and conga/cajon. Two acoustic amps: a little Fishman and a little Fender. Each of those amps has instrument and vocal inputs, so we each had our vocal mic into our amp, and the percussion wasn't mic'ed at all. It was plenty of volume for the venue, band make-up, and type of music. The only thing is that it was hard for us to fix our balance and eq. I don't think it was bad, but what with sitting close to our amps so we could twiddle knobs as necessary, and sitting behind them so the guitars and mics didn't feed back, I was wishing I could hear what it sounded like to the folks in front. Anybody have any super-lightweight, super-mobile, super-cheap solutions for band monitoring in a situation without a FOH PA?