I'm not sure about your area but there is a place in mine that does do it for a flat fee. I think it's $800 and they show you how to do a open house, show you the paper work and put you on MLS. But you have to give the selling agent 2.5%. It still saves you 3.5%.
And like alot of people here has said 6% is way to much. Real estate agents have had it very good for to long.