Bbot writes: “This is a neat little Canadian screwdriver which keeps its bits in the handle. Standard stuff — until you figure out that you change bits by pulling the center section out, rotating it, and pushing it back in. It’s the only screwdriver I’ve ever sat and played with. Great fun!”
The pictured screwdriver is the actual one bbot submitted (from Sears), but Froogle turns up quite a few sources for this particular type of screwdriver — in the same kind of price range: around $18.