Here's a short one. We want to know when this box was last rebooted. Sure, it's in the SCOM DB, but this is probably faster. The Win32_OperatingSystem WMI object contains the LastBootupTime attribute. Beyond that, it's a simple matter of converting that from WMI-time to [datetime]$time.
And, because computers may be in the middle of rebooting right now, they might not be pingable., hence the simple ping test.