Not the most obvious keyboard shortcut, but one I imagine Michael Kaplan knows all about I imagine. This switches the regional settings for your keyboard layout to the next one in the list. So, If like me, you forget to remove English(United States) from your installed region services after installing Windows, left alt + shift will often cause panic when @ becomes ", # becomes / and so on and so forth. The moral of this story, if you're not using an American keyboard, make sure you can't accidentally switch it back to American with an accidental thumb and finger combination.

Do this at Control Panel > Regional and Language Options > Languages tab > Details button > Settings tab.