I recently purchased a Blichmann Beer Gun, and the one thing I don't have to hook it up is a spare stainless steel flare/barb fitting.
I know you're not supposed to use copper in beer lines, because the carbonic acid in carbonated beer will leach copper from copper tubing.
I made up a fitting using a 1" length of copper tubing and a brass flare nut. Then I thought "Wait a minute". Then I thought, "Well, beer will be flowing through this 1" of tubing for only 5 or 10 minutes, so no significant amount of leaching will occur.
Any chemists out there?