The idea here is a general guideline. I pictured the concept in my mind and threw it together; I even eyeballed many of the screw placements & it still turned out pretty good. If you decide to do something like this you'll probably figure out the details yourself. The pictures are pretty explanatory I think; The key is the hanger bolt & tension nut at the bottom of the uprights. If you use real thin pieces for the uprights as I did, be sure to drill pilot holes for the hanger bolts otherwise you'll probably crack/split it. The hanger bolt & tension nut could be at the bottom or the top.
 

Lumber, shelf brackets, screws, bolts, pipe insulation and cable ties. All from a single trip to the hardware store and all for less than $25.00. Power drill, hand saw (all straight cuts!) about 1.5 hours, a few beers and you're done.
 
  The top blocks are screwed directly onto the uprights and there's thin carpet scraps tacked on them, to protect the ceiling. Cable ties hold the pipe insulation to the shelf brackets. Buy sturdy brackets; Wrap the pipe insulation around the brackets and past the sharp ends; Curve some of it up along the uprights.

A hanger bolt is a bolt that is threaded as a wood screw on one end and like a regular bolt/nut on the other. The wood screw end goes into the upright. In the center of the bottom block, drill a hole a bit wider than the exposed end of the hanger bolt and about 2/3's of the way through. This hole will act as a sleeve to keep the bolt in place and let you adjust the nut down against the washer for the tension to hold the contraption to the ceiling.

The measurement for the length of the uprights, in relation to the thickness of the top & bottom blocks, the tension bolt and the distance from the floor to ceiling, must be precise. You must allow for some "play" to adjust for tension. Take into consideration the thickness of the carpet too. One more view here.

Won't spend the time to get into minute detail here, but I'll answer questions as best I can