Houseplants Will Twitter You When Thirsty

Add one more nagging time-sink to your Twitter account: your houseplants. Botanicalls is a system which monitors the moisture level of your plants and lets them telephone you when they need water. Voice, though, is so 2005, which is why you can now add your plant to your Twitter list and have it message you when it's thirsty.
The principle is simple, but you'll need to be a confident circuit-maker to get the kit up and running. Two nails are pushed into the soil. When the humus is wet, a current flows between them. When that current drops, the Arduino-based circuit will connect to the Botanicalls network via a built-in, low-powered Zigbee radio and send you a Twitter update. It's up to you to actually water the plant. If you have arranged for a neighbor to take care of your flora, however, you can still keep tabs them: the plant will Twitter a "Thank you" when watered.