Hey guys,
I’m glad to see some people thinking of using the Pi for their sprinkler, I just wanted to let you know that I started a project in Go lang to handle the Pi with the Open Sprinkler. You might want to have a look.
http://pothibo.com/index.php/2013/05/31/control-your-sprinklers-on-your-raspberry-pi/
I know Go is a young language but so far, I’ve been happy with the results. If you end up giving my project a go and you need help, don’t hesitate!