Thanks Brian Haines
"Have you ever accidentally repositioned one of your ribbon bar tabs in Revit and were wondering how to get it back into it's original position? Notice in the image below how the "Modify" ribbon tab has been placed to the left of the "Home" ribbon tab.
To reposition the Home ribbon tab back to it's original location simply hold down the "Ctrl" key while dragging the tab back to it's original location....problem fixed!
The same technique will work for Revit Architecture, Revit MEP, Revit Structure and even works on Vasari which has just been introduced on Autodesk Labs.