All of these fit into a little pocket sized notebook, and you can clear things up ("Buy Pyra" "Go to the park on Saturday for the car show" "The following things must be done by EOD Friday" and receipt can be folded up). When you get home you can scan the recipt and put it where it belongs, or if you like paper, throw it in the folder with other stuff. Writing it yourself helps you remember why it is important, and you can still access everything when your fone dies (or is stolen, as happened to a family member this morning).