Well, let's think this through logically.
Sinus headaches are caused by pressure in your sinus cavity.
So, we just need to release the pressure.
Find a drill and a...mmmm...a small bit, like a 13/32nds bit. For a hole large enough any escaping pressure will be able to keep it open, but small enough that once the pressure is gone it'll still close easy.
Now your sinuses are right above and below your eyes and directly under your nose.
LinkYou'll need to open a hole into each.
There'll be a bit of bleeding, so keep some gauze around.
It also will probably hurt...a lot. But you can install valves into these holes so you can remove the pressure at will in the future so it'll be a good investment.
[Edited by Dhampy, 3/7/2010 7:43:43 AM]