If you haven't seen this, check it out.
Sailrite.com has lots of sail and trampoline repair, related parts and hardware.
They also have many instructional videos that free and accessible online. They discuss many interesting aspects.
Go to Sailrite.com and type "video" into thier search engin and the video catalog should display.
You might also try copying and pasting this entire link into your browser and then hit enter.
Anyone else have any tips or tricks?