No, I don't think I ever cheated in SSB:M, but I suppose that is a good example.
In Pokémon Red/Blue, me and my brother have had, on more than one occasion, played it on a Super NES (using the Super Game Boy instead), with an ASCiiPad (that was an awesome controller). If you have about 200 Coins or so (for the Game Corner), you can play a slot machine, flick the ASCiiPad to Auto-Turbo A, then leave it on overnight. Since the game is actually rigged, but in your favour, you'll find that if you play the slots long enough, then you're guaranteed wins that offset your losses (the 200 Coins to start is kind of a buffer zone). Every morning that I woke up to this, I had 9999 Coins, and if I didn't, I'd be in the 9900s, and just have to wait a few rounds before it'd max out again. Porygons were so easy to get this way.
Sounds like Nintendo is sending out a weird message about gambling. "Go on, keep playing, eventually you'll win more than you spent! Therefore...keep going!" o_0
My brother's left Ogre Battle on overnight to get more money...
I've set Lost Kingdoms II overnight to build up EXP of cards...by throwing down two cards of those tree guys who create a healing space...they constantly heal each other, so they never disappear until I say so. I throw down an attacker (like one of those guys that circles me) who can't die because of the healing, and making this mess of cards next to a cave where baby dragon enemies keep respawning, I've come back the next morning with powered-up cards with no effort on my part.
I'm sure I have more examples.
Now, back to the topic of the Wii...now that they're based on physical actions, you could probably "cheat", (like you said, not actually hula-hooping but making a similar enough motion) but overnight monotony like building experience or money might no longer be an option...unless I happen to have something in the house that can repeat a physical motion all night long without being seriously weighed down by the Wii Remote...