EVE Online grab you? Whoa, settle down there, Mr. flying-in-space troll, as we're not talking about Incarna-style player housing here but rather a new mechanic that seeks to add a bit more sand to New Eden's sandbox.
CCP Omen has the details in the latest EVE dev blog and in a nutshell, player customs houses exist to enable planetary taxation and to add a new wrinkle to the game's planetary interaction mechanics. You'll need to erect a customs office in orbit around a planet (note: there can be only one), and of course it can be attacked and destroyed by your fellow capsuleers.
For a list of materials, costs, and associated corporation functionality, warp on over to the official EVE dev blog.