(FORTUNE Magazine) – The Pentagon has come a long way from its '80s splurges on $435 hammers, but it still has a ways to go, according to a recent report by the General Accountability Office. For the 26 programs the GAO zeroed in on, R&D costs were 42% (or $42 billion) above initial projections. And those projects needed an average 20% more time than originally budgeted to be combat-ready. (Particularly egregious: the V-22 Osprey, 194% over budget and, at presstime, 14 years late.) Here's a look at a few of the most troubled military ventures. -- Peronet Despeignes