Of course, there's not a ton that toddlers are capable of besides the general pick up of toys.... and, to my great joy, using a spray bottle. Even better, Ben LOVES it.
I can't say he's the most thorough housekeeper I've ever seen, but my theory is that he can't really make it dirtier, so I'll take what I can get.
-- folding kitchen towels in half (I fold make the first fold and he makes the second)
-- putting said towels in the drawer
-- putting away the silverware (minus the knives, of course)
-- filling the dog bowls with food
-- setting the table
-- putting dirty dishes in the sink
It's not a lot, but it teaches him to pitch in and, I'm pretty sure, gives him a sense of pride... especially when he completes task with a loud "I did it!"