Other Layout Info
Another tool I ran across was a planning program
from Rain Bird. Here is the link, and there are more
instruction on their website. I've never used it before,
but it may work well. If you've used it please let me
know how it worked out.
http://www.rainbird.com/diy/design/index.htm
If you run into other layout trouble, your local
hardware store is often a good place to start looking
for advice.
I also ran across this tool on Orbit irrigation's
website. I've never used it, but it may prove useful.
Here's the link for the download:  
http://www.orbitonline.com/sprinkler-system-designer
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