Hi Nathalie, you've picked a great time to visit Walt Disney World and enjoy
Epcot's International Food and Wine Festival. There is a lot of information at the
Food & Wine Festival page, including the special Food & Wine themed Disney Gift Card, which comes attached to a stretchy cord you can wear on your wrist for easy access at all the great kiosks. That way you can load up the amount you'd like on the card, swipe it as you pick up your food and drink, and keep moving on to the next country!
Be sure to check back to that page above, or another great resource,
www.DisneyFoodBlog.com to see when they update to the 2010 festival menu information. That way you can figure out which items you'd like to try and calculate how much to put on your gift card accordingly (with a little leeway for items you decide you would like to try more of!). Most food items are between $4-6 while most beers and wines are in the $6-10 range. If you have anything left on your card, it'll still be good at every other location where Disney Gift Cards are accepted.
I hope that helps with your planning - have a wonderful time!
~Suzannah