Hi Lozey,
There's a trick with a toy robot on Eugene Burger's site (the essays bit I think) but a I remember he doesn't expose it, however, the workings are easily work-out-able (for those about to shout "fraud", he encourages the reader to do this...):
Basically, lay out five cards side to side, edges touching and work out with any wind-up toy how many winds it takes to get to a certain card from the edge. Then it's just a matter of controlling a card, suggesting that your powers are only good to a five card range and that you need your little magic friend to help you with the final section and Bob est ton oncle.
I tried this with some cool little tin robots, worked well but the tin toys were antiques and broke very rapidly

What's quite cool is you can plot it out to regularly stop on, for example, 3, but then with one extra or one less twist it will usually go to card 4 or card 2, so if the same kids see the trick again (and they regularly do if it's walk around) it doesn't matter.