I have a multi-monitor set up with my Macbook Pro. Frequently, when I move my mouse from one monitor to another, I'll assume I'm now working in the window my mouse is over, but find myself typing and having my old window/monitor accepting the input.
I've tried going to get the third party software site referenced in this previous question:
Unfortunately, the software they reference no longer exists
How can I change the focus just by moving the mouse?