Pallets actually make quite good gates. At our old house we had one simply wired to a wood gate post. It served us well, with next to no wear and tear for over 2 years.
Every homestead needs a compost bin and pallets are the perfect fit. You can make how ever many compartments you need, but I suggest starting with at least 2.
Again, if you have ever priced a hay feeder/hay rack, you will know that they are another necessary item that is way overpriced. We have made 2 hay feeders out of pallets that only cost us the price of the screws.
If you own animals, sometimes you might need to subdivide your barns and shelters to accommodate sick, young or birthing animals. Pallets are just the thing for this!
Gardeners have a lot of tools that can take up a lot of space. A pallet secured to a wall can hold all those long handled shovels, hoes, and rakes.
Photo via Nic Robinson on Flickr
Pallet Trellis from Lovely Greens