Paramount Pictures has bought the rights to the 'Old Man's War' series and have already pinned down Wolfgang Petersen to direct and David Self to adapt. Check out the plot description for the first novel straight from Amazon:
With his wife dead and buried, and life nearly over at 75, John Perry takes the only logical course of action left him: he joins the army. Now better known as the Colonial Defense Force (CDF), Perry's service-of-choice has extended its reach into interstellar space to pave the way for human colonization of other planets while fending off marauding aliens. The CDF has a trick up its sleeve that makes enlistment especially enticing for seniors: the promise of restoring youth. After bonding with a group of fellow recruits who dub their clique the Old Farts, Perry finds himself in a new body crafted from his original DNA and upgraded for battle, including fast-clotting "smartblood" and a brain-implanted personal computer. All too quickly the Old Farts are separated, and Perry fights for his life on various alien-infested battlegrounds.