Keyboard shortcuts - Today it's Alt + Tab

I find myself using Alt + Tab all the time.  It switches between windows - going back to the window you last visited and then if you do it again you toggle back to the one you just came from.  Unfortunately it doesn't switch you between tabs in your internet browser - but then it is easy to click on the tab you want.

So when I was drafting this and I wanted to go back to my browser to look for an image I just Alt tabbed it!