Really Useful Boxes are really useful.
Heard about them on boardgamegeek, found out that they have them at OfficeMax, and bought a bunch.
Not completely abandoning tackleboxes and ziplok bags, but Really Useful Boxes come in small enough sizes that it's great for pieces that get passed around (Small World races, if I really want to buy that many), or need to be "put back in the box" frequently (BSG ships).
They also come in gigantic sizes and lots of sizes in between, and they're nicely scaled. But for now, I'm sticking with the smallish ones.