This is probably part of the whole packing thread. But yeah I highly recommend buying disposable/emergency rain ponchos. They run around $1 each, maybe not quite as high quality as the ones they sell at the park. But they are much cheaper and easier to carry around. You don't need to dry and re-fold them at night, just toss and re-bring a new pack with you the next day..and the packs are extremely tiny and easy to carry in a backpack or purse. i.e. my fiance and i bought 8 which after shipping cost around $15, which is around the price of one ponchos at WDW. We threw away the ones we used at the end of each day, and we still ended up with a couple to use another day. It was nice not having to worry about drying and re-folding them after we used them. They also collapse really small if you only need them during certain times of the day.
~G
~G