i had seen this a while back and thought it was pretty cool so here ya go. if you've seen this before or it's old news, oh well.

click here (http://metalgeek.com/static/cope.pcgi)

basically you can enter 2 pipe sizes, the angles you want them to be welded at, and it creates a pdf that you can print out and wrap around your pipe as a pattern. no more gaps.

check it out.