How To: Make a M80

Source: http://www.i-hacked.com/content/view/13/48/

Here are your materials:
1-3/4" Tubes & Plugs (3/4" ID, 1/8" Wall, 1-3/4" Long)
Flash Powder
"Visco" Safety Fuse (Available at local gun stores, miliary surplus stores, and online)

Pretty much self explantatory afterward.