You have to use these on your friends quick though.  While you still have some!

Over the weekend I won $5 off a friend and got a free beer with one of these bets!  (I'm not going to tell you which one because I may have the opportunity to pull it on you someday.)

Absolute, no fail bets ... check 'em out!

One word of advice from Dubba G!  It doesn't hurt any if your friend is a few drinks (shots preferably!) ahead of you before you try these!