Recently, I received a very warm email about a site I did not know existed http://www.yeshivalive.com/mr. It is maintained by Akiva Sacknovitz, who told me about it, and contains six years of Rav Rosensweig's shiurim that he has given at locations such as Adath Yeshurun, Kew Gardens, NY and currently at YI of Jamaica Estates, Jamaica Estates, NY.
As Akiva stated these shiurim are " geared to the working individuals. Since the shiur is only once a week, he does not cover as much as he does in his daily shiur, though all his insights and approaches to the sugyot are still there. He does not assume that those in attendance have seen the sources inside and he does not bring the plethora of proofs that he normally does in his daily class."
The masechtas Rav Rosensweig covers are Kesuvos (2002-2003), Sanhedrin (2003-2004), Shabbos (2004-2005), Kidushin (2005-2006), Bava Kama (2006-2007) and Chulin (2007-2008).
I have downloaded all six years to my iPod and have begun with Kesuvos.