The core of the earth is a giant magnet. Really. It's an iron core, and that's one of the main things that gave The Earth a magnetic field to protect us against part of the deadly laser in the sky.

I don't think it would have enough magnetic pull to take pens and lighters from the surface though. Also how does that account for all the missing socks I hear about? I don't think that cotton/polyester blends are magnetic.