go to Home Depot or whatever is around you..
buy some chain, enough that'll fit around the branch you plan on hanging-- $2
a small C clamp that screws together- $1-2
a trampoline spring, that is completely closed on the ends - $5-6
rope, how ever long you need it- $2-?
now take the chain and wrap it around the branch
take your little clamp and hook it through the ends of the chain and on one end of the spring..
your half way done now..
take your rope with a knot tied in one end and slip it through the other end of the spring..
tie a toy or simply knots in the rope on the other end of the rope and your done
here is what it looks like
i have to change the rope every now and then because Diesel has razor sharp teeth and cuts off sections while he's doing this