The other day I was doing some testing with different Windows accounts and needed to run a bunch of tests as the Local System Account. Normally I can use runas to get a CMD window for each user I need to test with. But Local System Account is special and you can't just do a runas for it. I don't know why I didn't think of these, but there are at least two ways to get a CMD.exe running as Local System Account, setting it up as a service or using an "at" command.
Find out what's on Clearance at ThinkGeek!