We just moved into our new house and want a retractable screen door for a balcony off our master bedroom, but we don't want to deal with installing it right now (the door opening is an odd size and we'll probably have to hire someone to cut it down and install it). I found this blog, and figured I could do something similar for pretty cheap. I don't sew so I used a glue gun to make the sleeves. My personal little trick was to use a cheapo silver eyeliner to mark on the screen material. I also added another tension rod at the bottom because we wanted it to be able to keep our cat inside. If we're going in and out I just take the bottom rod out. The screen material and rods cost me all of $12, and it took about an hour.
I'm guessing it looks better sewn and would probably be easier with a sewing machine, but this wasn't too hard and the end result actually looks better than I thought it would.
Door (it's really hard to take pics of a screen door!):