Xtra Bic lighter and a pepsi-g stove to back up my pocket rocket. Seems isopro can be hard to come by sometimes and at 1/2 gram the pepsi-g is cheap insurance. Also clean dry socks and extra gloves in winter will always be in my pack. ClO2 backs up my filter and Stanley makes a really light tripod light that uses watch batteries which backs up my headlight. I think that's it.

BTW- has anybody seen the baseball cap w/built in light in brim? My buddy picked one up from Lowes. Forgot to ask how much he payed though it looked well made.