Check out the Uni-ball Power Tanks. Power Tanks at Office Depot They are similar to the Fisher space pens in that they are pressure fed. It writes wet, cold & upside down. Cost is about $3 each. I use them for taking notes at work & in class & keep at least a three pack in the armrest or glovebox of the car. The retractable version is comfortable enough to get me through 4 1/2 hours of class notes or longer.