After reading the November '06 "Manifest and the fusion cache" blog entry that one my peers wrote, I immediately thought about the *nix style TOUCH utility.
But it's not available out-of-the-box on Windows... I was surprised to learn that the Updating the Date and Time Stamps on Files trick worked well on Windows 7.
All thanks to our old MS-DOS command:
if %1.==. goto end
if not exist %1 goto end
copy /b %1 +,, > nul
echo %1 touched!