Check out the tutorials on Doddies Zoomer’s Instructables page on how to build fun and unique outdoor wood burners. They are the kind of thing that will make your neighbors jealous, win you friends, and impress your boss.
He also touches on this important safety note:
Firstly make sure your bottle is empty, remove the brass gas tap from the top and fill with water. This will displace any left over gas and make it safe to cut into.
This can not be over stated. Even if a container you are going to cut into only had a semi-volatile liquid in it, fumes from that liquid could still be combustible and combustible fumes + enclosed container + sparks = emergency room hilarity.
Use water to flood the containers then get cutting and make something cool!