I kept a packing list using HandyShopper on my Palm for many years. Before every trip, I go through it, selecting the necessary quantities of everything, then I pack all those items and check them off. This greatly reduces the rate at which I forget a random item.

Now that I've upgraded to the Palm Pre, using HandyShopper through an emulator is a bit clunky. I've considered some of the new WebOS apps, but I would possibly prefer something I could access and change over the web, not just on my Palm. Any suggestions, web sites, or software that works for you?