Mountain Hardwear Pinole 20 Sleeping Bag $50 + Free Shipping

until someone farts

If you were buying it from Walmart I'd agree but the brands sold at REI are pretty reliable and spot on. In fact, I bet this bag would keep you warm enough even slightly under 20 degrees.

How the fark does anyone fit in a regular length bag?

I need a down bag rated to 0, long and cheap as possible. Need a deal under $100 preferably.

I would not risk being caught in 20 degree weather with this bag. Bag ratings are iffy at best. Some bag manufacture rate their bags assuming the following:

You are in a good tent
You are on a good sleeping pad
Sleeping pad is 3/4" or thicker
You are wearing long underwear
You are in good shape
You actually fit your bag properly
Your body runs warm/cold etc

lots of variations in how bags are rated. best bet is to get something warmer or to actually try some bags before buying.

Mountain Hardwear Pinole 20 Sleeping Bag - Regular - 2012 Closeout [rei.com]

Soft, compressible Thermic MX™ fill is engineered to provide superior warmth and minimal weight
Offset quilt construction means no sewn-through seams and no cold spots
Warmth is optimized through differential cut of shell and lining fabrics, allowing adequate room for the insulation to expand to its full loft
Slightly wide cut gives you extra room to move inside the bag; comfort mummy cut efficiently maximizes warmth without constriction
Tailored hood with face gasket forms around head to seal in heat
Comfort footbox allows feet to rest naturally, angled out slightly with toes pointing, while fully preserving insulation loft for maximum warmth
Insulated draft tube (backing the 2-way, full-length zipper) and insulated zipper gusset seal in heat
Antisnag construction prevents fabric from catching in the zipper; locking sliders keep the zipper in place for ventilation options
Comes with microfleece-lined stuff sack that doubles as a pillow
Closeout