Raspberry Pi watering system

This is a pretty good idea, a little overkill for me, but if you own a greenhouse…Anyways the author is bypassing an existing water controller and using a RPi to get weather info and see if it should be watering or not based on weather reports, etc..  I like this idea but would scale it down.  I bought an automatic timer for watering the garden last year, and it works great, but really bothers me that if I don’t remember to turn it off, it will water the garden in the middle of a rainstorn.

http://www.thirdeyevis.com/pi-page-3.php