Whether a cross-country PCS or a fun weekend trip, traveling is more fun (and a heck of a lot less expensive) when you're not stopping every hour to buy something that you've forgotten. I've been scouring the internet for packing lists and I've found a few good ones at OneBag.com, Rick Steve's website, at About.com, and at a site appropriately called Packing List Advice.
Here's my own personal list of things that I regularly forget (or purposely don't pack and know that I'll have to buy as soon as we arrive): zip-top bags, beach toys, a cutting board and knife, a wine opener, nail clippers, and paper towels and/or baby wipes.
Over the years, I have randomly begun working on various packing lists but have never made a good one. I can't even begin to figure how much time and money I've wasted wandering around some mega-store searching out last minute items. In the future, I think I'll just print off one of these lists and adapt it to my own needs. Maybe that way I'll spend more time in the sun and less time in the stores!