I have a little backup program that I wrote that includes the ability to shut down the machine when a backup is complete. I wanted to add the option of putting the machine to sleep instead of shutting down, but it took me a while to figure out how to accomplish this.
After using WMI to implement the shut down code, I thought it might be an equally painful process to enter sleep mode. Once found, however, the solution is very simple: See System.Windows.Forms.Application.SetSuspendState.
Application.SetSuspendState(PowerState.Suspend, true, false);
I guess my problem was that I was Googling for the user-centric term "sleep" instead of searching for "suspend", and if you throw "sleep" and "C#" into a search, you tend to get a lot of threading results.