I want some evil punishments...

[Kristev]

No, I've got it. They have to read my novels. All of them.

[Jester]

Make them listen to Justin Bieber, or read the Twilight novels.

Oh, wait...you said nothing that could cause permanent damage. My bad. Let me try again.

For those of legal drinking age, have them drink warm gin. Even gin drinkers generally find this disgusting. Also, warm flat stale beer, or cold stale coffee.

Make them drink a lot of liquids, and then not allow them bathroom access. Basically, make them pee their pants.

Shave their heads. The whole family.

Make them dress in clothes two sizes too small. Including underwear.

Wedgie from Luther the Biker, or some similar large badass type.

Sadistic bikini wax for the guys.

[sstabeler]

Make them drink a lot of liquids, and then not allow them bathroom access. Basically, make them pee their pants.

that might be going a bit far, actually, particularly since it's the kind of tactic that a bully might use. (specifically making them pee their pants)

[April]

They have to trade phones with open access with each other for the day...access to FB, hang outs, text messages, etc.

Lie detector tests full of embarrassing questions written by other family members

Locked room escape style game, but youre locked in with your in laws