ultralight fire piston

http://goinggear.com/index.php?main_page=product_info&cPath=6&products_id=3088

This one is 2 oz.

I'm a bit of a "Paleo Pyro" and so I have experimented with a lot of traditional fire making techniques. I have a couple I have bought and have made a couple fire pistons. They do work well with a little practice, the right tinder, etc.

Personally, I'd take a firesteel any day. Much less finicky, don't have to have "perfect" tinder, worry about carrying lube and gasket material, etc.

That being said, people are really impressed when you start a fire with it (or a hand drill or bow drill).

I don't think you can find a fire piston hat will be lighter than a small fire steel like the miniature one I have from here:
http://firesteel.com/categories/FireSteel-Blank-Rods/

It says it weighs 3.7 grams and it is definitely usable. For a striker you can use a 2" piece of a hacksaw blade. I put a wire terminal on the end and this what I have for a waterproof reliable fire starter (along with a small ziploc bag of dryer lint). It weighs 10 grams.

Here's a titanium one though I'm not sure of the weight. He does custom work too I'm sure if you wanna make it smaller.
http://tisurvival.com/main/products/fire-pistons/