My friends bunnies have these and I'm hoping to get some next time I'm there http://www.ikea.com/gb/en/catalog/products/20116943 They love them, running into them, putting their paws up at the back and rolling them around!
Wow! I'm pimpin' the hutch at the moment (I will post pics when I'm done) and have just come across these, shall I do it (o/h won't be amused but sod him)
I like that.............. might get one for the front of their wendy house.