This one could have some really interesting tech spin-offs

"The 100-Year Starship study will examine the business model needed to develop and mature a technology portfolio enabling long-distance manned space flight a century from now. This goal will require sustained investments of intellectual and financial capital from a variety of sources. The year-long study aims to develop a construct that will incentivize and facilitate private co-investment to ensure continuity of the lengthy technological time horizon needed." http://www.darpa.mil/news/2010/starshipnewsrelease.pdf