There is a whole lot of designer water products around. Probably the most over the top is O18 from a company in Chatswood. They are selling water which is derived from apples and oranges, and then purified. Sounds rather expensive, and basically ‘over-engineered’.
Mitsubish has a strange report on how LED’s can be used to sense the ambient light level. This is strange since LED’s are supposed to be output only. I think I understand some of the theory as to how this works, but it really is a bit beyond me. More information as to how this works in practice is available here.