I came across this in another online forum and thought I'd pass it along. For a novice welder like me, this is a nice tool and it's free!
There is a program called Tubemiter.exe that when you input your tube size, it will print out a template. You tape the template around the pipe and then cut the pipe to the template. Perfect fit, ready to weld.
Go to the following link and near the bottom is a program description with page print outs so you can see what its doing. You can also down load the program there. The program is FREE and will fit on a floppy so a old laptop in the shop or road would work well to have this with you.
Damon Rinard's Frame Building Links