Favorite amazingly useful trivial convenience

[Blarg]

Let's leave out the things we all or almost all have -- fridge, car, lightbulb; let's leave out the super-common like a cell phone or a microwave. Let's leave out the dumb, like: a spoon, a manual can opener, or a bookshelf, to...uh...hold books.

What's your favorite seemingly trivial convenience item that seems to provide outside rewards for what you spent on it? I have a feeling tivo is going to be a big one here.