What kind of emergency fire starter do you guys carry when out in the field?  In your emergency pack?
I've had one of the Magnesium/Flint starters for years, and have tried it a couple of times, but I guess that I trust the Zippo first.  Can be difficult when it's wet, though.  Same with a Bic.  
What about tinder?  Steel wool?  Singed cotton?  Paraffin mixes?  Those sawdust "firestarters"?

Much the same as Troy.  "Kitchen Matches" (in waterproof container){the main matches I use for everything}, MRE Matches, a lighter, some waterproof matches hidden deep, and a Strike Force Fire Starter with Wet Fire Tinder.  This last item is a bit heavy, but it is self contained and works every time; the tinder works great and can be reused by cutting off the air.  Most of the time when I'm out in the woods I don't mess with a fire, but if I need one I'm going to get it started.

i keep one of the compressed trioxane fuel bars in my pack...along with a lighter and some strike anywhere matches. the fuel bars were orignally designed to heat mres in the field, but they work better than anything else of comparable weight and volumne that i have found for firestarting.

i also like the cottonball/vaseline combination for a homemade solution.

ChapStick on a field dressing works nice.

Matches N' Wax - measure and cut a small piece of corrugated cardboard so that is is slightly wider than standard strike anywhere matches.  Push them into the recesses in the cardboard, alternating the match heads on opposite ends and soak the whole shebang in  warm paraffin.  Repeat as necessary.  When the chips are down you have an inexpensive match that will light in the worst conditions and the wax soaked cardboard makes superb tinder.  I have used these for 25 years in the N. W. and never failed to get a fire going no matter how wet and windy the conditions.  As Troy notes, cotton balls soaked in vaseline are also superb and will work in wet, windy conditions.  I use a small plastic film container to carry the cotton balls and vaseline.  The container and the cardboard will fit in a shirt pocket and keep you safe for a long time.

Thanks, fellas.
Hadn't thought of including a hacksaw section.  That ought to save my knives.

Will stir up some of your recipe, Fox.  Sounds like a good thing to throw in the pack.  Better safe. . .

Have a resolution to start a fire with bow and drill or hand drill this summer.

Little slices of tire rubber will burn even when wet. This will help a lot if you can't find any dry kindling. Mix the rubber slits with some wet kindling and light the rubber. 10 minutes later.....[flame]

Small tin of sterno, magnesium ribbon neither have ever let me down. I live with a lot of wet/dry snow from November to late April. Put the sterno in a small tin and wrap it in a baggie, the Mg ribbon is better because you don't have to shave it, and it burns with a vengence.