<p>How can I send a monitor into/out-of a different power state (like sleep)?</p>

The latest version is maintained on IDesign's site here:
http://idesign.net/Downloads/GetDownload/1887
Older version are available on the O'Reilly site.
Programming WCF Services 3rd Edition (PWSTE) Samples:
http://examples.oreilly.com/9780596805494/
Programming WCF Services 2nd Edition (PWSSE) Samples:
http://examples.oreilly.com/9780596521301/
I found this via:
http://oreilly.com/catalog/9780596521301/
and clicking on "Examples"
Download the zip file and it has all the code for ServiceModelEx. I hope this helps.