I picked this guy up at the thrift for $20. I would like to make a single speed out of it for a winter commuter bike. What would be the easiest cheapest way to do so. The down side is it does have vertical dropouts. What can I do?

Easiest, cheapest way is to choose what gear you want, take the rest of them off, and add spacers. Store-bought they're about 10 dollars. You could get some spacers from an old cassette, or make your own out of the right gauge PVC if you have the proper tools.

Then take off the shift lever and cable, and set the adjuster screws on the der to keep the chain tension right. I think you're looking at $10 if you do it that way.

Or you can get a SS conversion kit with a cog, spacers, and tensioner. That's like $20 over on ebay.

One of these: https://www.jensonusa.com/store/produ...rsion+Kit.aspx
And one of these: https://www.jensonusa.com/store/produ...Tensioner.aspx

Find them on eBay for much less, though. Then ditch the shifters, rear derailer and cable, and you're pretty much good to go.

what about savoring the amazing deal you got and ride it until the deraillers fail and then worrying about converting it to single speed?

it's set up pretty nicely, add a set of fenders and a set of lights and you've got yourself a really solid, nice commuting bike, i wonder what happened to the bike's person that such a nice set up would wind up at a thrift shop....?

^ +1
Use the money you save on the conversion for new tires. Will you be riding in the snow? If so, get some of the biggest tires that'll fit.
Is that crank set a double? If so put a MTB bash guard on it. They are meant for off road riding to protect your chain rings, but they serve an extra purpose of protecting your trouser leg from getting stuck in the chain.

Also, MTB's look much better with bash guards

Sell it for $300 and get a Bikesdirect SS bike. That is a killer deal, I think it is too good to be true...

just get a surly singulator and spacer set if you want to single speed it. you'll also probably want to add a front brake too.

i'm jealous this was a damn good find man.

Yeah, unless the derailleurs don't work, keep them and put on a front brake.

Sell it for $300?! The bike was $400 brand new and that was with a triple crank, fenders, and a front brake.

OP: Does the rear hub use a freehub body + cassette or just a multispeed freewheel?

You can get the Origin 8 conversion kit with spacers, two cogs, and a tensioner for $30 shipped on ebay.