We give our children Disney dollars and pins for doing extra chores. They are still responsible to do their normal chores (make their beds and keep their rooms tidy, empty the dishwasher and clear the dinner table).
Their extra chores can be anything from changing the cat box to polishing furniture for me. If they perform extra chores, we pay $2 a chore. If they do 5 extra chores a week (the maximum) they earn $10 + a pin to trade at the parks.
We pay out extra chore money in Disney dollars. This works out like a dream for us.
I get extra help around the house, they learn the importance of earning money and they have their 'own' spending money at WDW.
I buy the pins on Ebay in lots of around 10 or so. I usually pay about $2.25 a pin. I never really pay attention to what is on the pins, just that they are traders and cheap in price.
This helps in that the kids actually want to trade those pins and I don't end up buying traders at the parks.
My kids enjoy Visa/Mastercard gift cards, but you need to know your balance at all times. If they only have $5.34 and an item is $5.50 the card will decline. This is frustrating for younger kids and parents. I don't want to take time out of my vacation to 'balance' my childs gift card and younger children don't have quick enough math skills to perform the balancing on the go.
One last tip.... our kids used to be the annoying "Are we there YETTTT?" kids. A lady at dh's work taught us this tip: give your kids a roll of quarters before you leave home. Each time they ask are we there yet, they have to give up a quarter. Once you reach your destination they get to keep whatever they have left. This worked like a gem when they were littler, now we give them 10 $1 bills and it works very well. They were willing to part with a few quarters, but not a whole dollar.