Butane is nice but I wouldn't give my Zippo up for anything! Being around salt water flints can go in 24 hours from corrosion (same if not worse with electronic ignition) if the lighter gets wet, with the Zippo I always have spares in the bottom which is relatively sealed.
As for fuel, the Zippo will work on about anything... last month I was at Disney (not smoker friendly) and ran out of fluid. It took me about 10 minutes to think of something flammable in a theme park but at last... The first aid station! The staff was not very impressed with my resourcefulness and promptly explain that they would have refused my request for alcohol if they had known I was going to use it to 'aid killing myself'... none the less I was quite tickled with myself.
It also works great for cutting fishing line and string with the lid clasped over the line and giving a quick jerk, the body edge as a flat head screwdriver, and the inner spring to jump a blown automotive fuse (which has gotten me home on a motorcycle twice), to make a clicking sound to annoy others out of a room, etc <img src="images/graemlins/blush.gif" alt="" />)