This is a great idea!
I've been saving all my old bottles, making rafts and using them to waterproof the outhouse roof, and as junctions between the gutters and rainbarrels.
Not yet! I've just got back from two months away and the state the boys let the house get into I'll be needing shovels and brooms rather than little hand brushes for a few days...
I'll post a report when I've cleared out a bit and had time to try making one.