Marmot Mountain Works has the WM Mitylite at 30% off, which is a steal.
http://www.marmotmountain.com/MMWmain.asp?Option=Detail&StyleID=10191
My wife and I use this bag as a 2-person quilt for lows of 40 and above. The bag weighs 1 pound 10 ounces and we zip it to an 8 ounce homemade "summer coupler" that has sleeves for both our thermarests. It's extremely comfortable and just 2 pounds 2 ounces for both of us.
Also the shipping is free and tax is only in CA.