Check out IPS's Unified Security Budget

If you want an excellent analysis of our military budget, and suggestions for ways we could both make ourselves more secure while saving large amounts of money, you should check out the Institute for Policy Studies (disclosure note: I am an Associate Fellow at IPS) study, "A Unified Security Budget for the United States, FY 2009".
Here is the link: http://www.ips-dc.org/reports/#676
The report was put together by a task force of experts, led by Miriam Pemberton of the Foreign Policy in Focus Project at IPS, together with Lawrence Korb of the Center for Defense Information and the Center for American Progress. I know Miriam well, and she is one of the most astute analysts of our military budget.