Rabbit play pen. Ours used five 2x4's (cut in half length-wise). Then use one of those to make the uprights(two feet tall). (all boards become 2x2's) One roll of chicken wire will keep the bunnies in. Great for the kids to be able to play with the rabbit in the yard.
Cheap and easy DIY toys for small pets. Just use the toilet paper and paper towel rolls you're already throwing out to make affordable toys for chinchillas, rabbits, guinea pigs, rats, and other small pets.
I am starting this for Winnie.. use organizer cubes as walls for a rabbit habitat. Hold walls together and carpet/grass to the floor with zip ties. Use a shower liner around the bottom to protect flooring.