We found a site, 50 Things and Beyond, which provides check lists for all sorts of projects like parties, gifts, holidays and travel. Print out their lists and tweak them to suit your needs. For our packing list we added Ipod, travel speakers, phone charger, curling iron and sunscreen. They give you a great start. Besides it's always the obvious things we forget: like a bikini or sunglasses!
Happy travels (and packing)!