Since we first reported on hydrogen burning micro-turbines back 2001, not much has changed. They're still one-of-kind research and development items. But, with continued delays in small fuel cells, it's still possible micro-turbines could be available first. A new TechnologyReview.com article brings things up to date with news of a dime-sized, 1M RPM, micro-turbine on a chip developed by Alan H. Epstein and other researchers at the MIT Gas Turbine Lab that can produce either 10-50 watts of electrical power (much more than fuel cells of equivalent size), or 10-30 grams of thrust (handy for making tiny, jet-powered MAVs). Like previous micro-turbine designs, MIT's uses pure hydrogen for fuel. For more details on MIT's approach and photos of the turbine itself, see Epstein's 2003 paper, Millimeter-Scale, MEMS Gast Turbine Engines (PDF format).