Barrel o'....rain

I have come into a pair of 55 gallon drums with which I plan to make rain barrels out of. Apparently they already have 2" bungs. I don't know what that means but I blow snot out my nose every time I see it.

I am getting them off Freecycle, which is not as good as the "free" listing on Craigslist but it's more popular out here. I hope to pick them up on Saturday. Perhaps a visual documentary on my rain barrel making journey is called for?