Registration is required, but is probably worth the trouble over at NanoMarkets, where they have a series of free white papers on nanotech, including "Thoughts on the Economics of Nanosensors" and "Plastics, Nanotubes and the Mobile Displays of the Future", plus multiple reports on nano-enabled drug delivery and drug discovery. Excerpt on sensors: "NanoMarkets believes that nanosensors are unlikely to dominate the sensor market anytime soon. In fact, our forecast of the nanosensors market indicates that nanosensors will likely not achieve a 10 percent penetration of the total sensors market until early 2010. However, in light of the total size of the sensor market, even minimal penetration means that the nanosensor market will be worth a few billion dollars within just a few years, which makes them a market opportunity well worth pursuing." Of course, if you love the free white papers you can buy the big reports for big bucks ($2K+).