I'm sure most of you know that you can change clubs by using the roller on your mouse. This is handy, but it just cost me a good round. I was ready to tee off on a par 4, and accidentaly moved the roller forward,changing the club from driver to my 64* wedge. I didn't catch it until after the shot was hit, and it dumped it in the weeds about 50 yards off the tee. I couldn't get it out of there and finally aborted the round. Of course, it had to happen on the last hole.
So when you're ready to hit a shot, take one last look at the club and make sure it's right before swinging. I learned this lesson the hard way; hopefully this will help someone avoid my stupid mistake...