We call messenger bags "Jack bags" because Jack Bauer of 24 made them look so cool. This one got thrown together with some household items, so it's kind of a MacGeyver/Bauer hybrid.
It's cheap, it's easy, and you'll never cry if you wreck it. It's the Jack Bag!
Step 1: Tools & Supplies
Tools & Supplies:
Stuff not pictured because I'm disorganized:
Iron-on patch compound