2 Twisty Tie Spool
I'm busy setting up my Makerbot, and I don't want to go out and buy a spool, so what do I do? Use the two twisty ties that came with the plastic to hang the roll from the nearest available surface of appropriate height...
Every 5 minutes or so during printing you have to give the roll a turn, so this isn't a long term solution, but this will get you going long enough to print out a spool.