There are lots of dumb toys you can buy for your rabbits, and rumor has it that they like hard plastic baby toys too, but my rabbits' favorite activities are practically free. They have a large cardboard box filled with crumpled, heavy paper, and they've gnawed their own entrance and exit holes for the box, so now Jupiter loves to go into the box. I think all he does anymore is just move the paper around, but it entertains him for hours. Juno's favorite is shredding. We gave her a phone book, but she mostly ignores it.
Juno prefers magazines. Newsweek is a particular favorite. Here she is, shredding Sarah Palin's face. (I frequently have this urge myself, but, not being a rabbit, I restrain myself. Sometimes with great difficultly.)
It's amazing how fast one reasonably small rabbit can totally demolish a magazine. Honestly, if I had sensitive documents, I'd just hand them off to Juno. No one would ever be able to piece them back together - especially when you consider that every so often she eats some of the source material! Sometimes Jupiter gets in the game too, as I imagine all that tearing and clawing is nigh unto irresistible, but he's not the pro that she is. When she finished with Palin's face (and the rest of that week's Newsweek), Juno moved on, taking out a spread in Sports Illustrated about the Tampa Bay Devil Rays. (Hear that Phillies? She's totally on your side. Don't let her down.)