get a soft case- you can stick it under your seat.

i've a diy pup prop- made from the plastic handle off a pop bottle + a wooworkers 'G'clamp-50p from local market.

Dave Bryant, liked your 'blue tack' hint- good for stop-gap.

i use it for holding my plectra to the guitar. ['cept mines 'white tack'- a lot of people think i've got 'em stuck in chewing gum!]