Twitter Enable Your Plants
A friend of mine twittered this product it looks like a leaf made of circuit board that you stick into the soil of your plant pot. It is actaully a sensor and twitters when it needs to be watered!
Twitter is a social networking microblogging thing which if you can become addicted too – this means this would actually really help keep your plants watered 
or to stop you over watering.
It’s a make it yourself kit which also looks fun. This post translats as I want one or maybe half a dozen of these! They came from one of my favourite companies – Think Geek
Now you have to be able to solder to make this kit up so if anyone wants to bribe me with curry to assemble them I just might
What I would like to see though is ones that I could connect to a nabaztag mainly so the plant in the office doesn’t die! or maybe just an email alert/txt message alert system. I am wondering now how hard that would be to do?
Also sensors that detect other things might be a cool idea