Shower Gadget - Holiday Gift Guide for Gadget-Loving DIYers - Bob Vila
Waterpebble Water Saver
By memorizing the time of your first shower and using it as a benchmark, the oh-so-clever Waterpebble indicates (via a series of "traffic lights" that flash from green through red) when to finish showering. Each time you shower, Waterpebble fractionally reduces your shower time, helping you to save water without needing to think about it. Available on Amazon; $9.95.