I have a butane conversion in my Zippo. The Tobacco Shop sells a $14.95 KGM Vector butane lighter that is such a close copy of the Zippo that you can just pop the butane insert into the Zippo case.

No more evaporation, and it uses the stock Zippo flint. On the downside, opening the top starts the gas flowing, so you can't open/close/open/close/open/close/open/close/open/close/open/close just cause you like the sound.

I also have one of the permanent matches in my Ritter PSK.