I was toggling between layout views (Default, Animation, etc) and I accidentally got this:

I don't know how to simply restore the "Default" layout... or any layout. Many of the interface elements are gone and I was able to bring back some by clicking "maximize area" in one of the tool bars
So, anyone knows a way of restoring the default layout without using the layout button? thanks in advance!
(I've tried searching and apparently no-one had this problem before...)
Ctrl+LeftArrowandCtrl+RightArrowto switch layouts. – gandalf3 Dec 30 '13 at 22:56