Remember back in January 2006, when British secret agents were caught planting a fake stone in Moscow, kitted out with espionage gear such as microphones and cameras? I imagine that the international scandal inspired the company Wiedamark to create these lights disguised as garden stones. Not exactly international espionage, but still darn sneaky.
When the power’s off, they look just like an average garden rock, presuming you live in Cornwall or somewhere where rocks in your garden are an everyday occurence, but when switched on, the LED lights inside cause them to change red, blue and green. Waterproof, and floatable, there are three different designs for $34.95 a piece.