How exactly would I make both of my monitors go to sleep, I want to write an application myself because I'd like to add certain functionality, and so far I can't find anything on MSDN relating to making your display go to sleep.
You want something like:
SendMessage(HWND_BROADCAST, WM_SYSCOMMAND, SC_MONITORPOWER, (LPARAM) 2);
It should work on dual monitors.
Although it might be best not to use HWND_BROADCAST, but instead to use a HWND from your app's own window. You don't say what language you're using, but if it's C# or VB.NET, there are plenty of samples about demonstrating how to call this from those languages.