Pressing P leaves Blender frozen, how to get undo? I was rigging a foot to a skeleton when I meant to click CtrlP, I pressed P. Nothing happened so I then clicked CtrlP and my entire skeleton and avatar turned white. My mouse does not show up inside the Blender screen and I don't want to close it and start over. I did save but I'll still lose quite a bit of work.

Is there a button I have pushed that can be undone via the keyboard?
If this happened when you pressed P, you've started the Game Engine preview. Press Esc to return back to your normal view.