Like shipping pallets, wooden cable spools are another item that is usually found for free on Craigslist. Since cable spools are limited by their shape there are fewer repurposing options, but they make a great coffee table bookcase.
Drink Umbrella Wreath - Here is a great fun idea for a summer wreath for your front door. Get a Styrofoam wreath and stick a ton of fun drink umbrellas in them. This would be so great to put out while hosting a luau or summer swim party.