How to revert file in Visual Studio 2010 (reload the file from disc)

Unfortunately I do not know of a built-in way to do this in VS other than closing the file and reopening it without saving.

There might be some extension that does this, but I am not aware of it :(

In the current version, you find in the Explorer, in the left sidebar. Then Open Editors, and right click on the file you want to revert.