We've looked at a few of the product catalogues, but that's about it. Part of a comprehensive program to look for these devices would be to translate the operational requirement into a technical requirement and then look at the devices available that meet that technical requirement in principle and according to the manufacturer. Then they would have to be evaluated in a wide range of circumstances, because the technical requirements—or the catalogues, if you will—provided by the manufacturers tend to tell you the best performance in the best-case situation. They don't really allow you to truly understand the limits of the devices. So you'd have to go out, buy some of these, and test them.
On February 14th, 2012. See this statement in context.