The act of using the ALT+TAB keys to jump from application to application (Or document to document), or in the workplace, using those keys to hide the website of non working nature to go back to an open document looking like you're doing real work.
I hate that I can't alt-tab between Visio documents.
When Art heard the boss's footsteps, he quickly alt-tabbed to a spreadsheet, hiding the streaming pr0n he had been lookin at.
To overtly change the subject of a conversation.
I'm going to Alt-Tab us right now back over to what we were talking about previously: Brown Chicken, Brown Cow