13. Upcycle Giant Spool into an Outdoor Science Lab
Tutorial: tpcraft.blogspot.com
14. Make Your Own Bottle Opener from Scratch
Tutorial at shanty-2-chic.com
15. Pallet Wood Garden Walkway
16. Create a Sunken Trampoline
All you really have to do is to dig a hole the perfect size and drop the trampoline into it.
More details: littlegreenfingers.typepad.com