Check out this amazing video that I found on a blog called Holy Scrap Hot Springs: Reckless Experimentation in Truth or Consequences. Wendy and Mike make a super cool bench out of old pallets . . . ya know, those wooden slats nailed together to move large amounts of materials. I suppose it would be best if you were going to upcycle pallets to use ones that are no longer useful for their intended purpose (those with broken or rotted planks, etc.). Anyway, here's what the bloggers had to say about the very simple process and materials:

"Wendy and I spent the day working on our pallet chair. It is really more like a small bench. The project was quite easy. I think we did the whole thing from beginning to end in less than four hours with really no plan in place. The only thing we used besides a fancy pallet was six bolts (+nuts and washers), a few feet of 1x4 to fill in some gaps and a bunch of 3" screws."