Rabbits enjoy being groomed by owners, its establishing the pet bond and also is good for your pets skin. Grooming is very important to avoid hair balls - especially important for long haired rabbits.
Rabbits grooming themselves can eat lots of hair which isn't digested, and which will travel through the gut, and oddly knot together with more hair forming long 'ropes' and pellets of matted hair. These commonly cause low grade pain or even full obstruction. Unlike cats they don't vomit hair balls (rabbits can't vomit or even burp!).
Nails need checking and trimming regularly.
We are looking around for fun items, and the Crinkle bags although originally designed with cats in mind are great fun for house rabbits.