I have a client that has told me on more than one occasion that she has to have variety when she works out. Otherwise, she will get bored. So she works out with me to do strength training, goes to sunrise yoga at Willow Street Yoga and has hired my swim instructor to help her in the pool. She certainly gets variety.
Well, how is this for variety? There is a trainer at the Tyson's Sport and Health Club that has come up with a "Spartan Workout" that is based on his experiences working on a farm. The workout includes lashing ropes, flipping tractor tires and slamming a sledge hammer. Sure, it might sound kind of crazy, but if any of you are into gardening or yard work (or do it anyway even if you are not "into it"), this workout could be considered "functional exercise" for you.
I have done a workout where we flipped tires before (there is a picture of it on my Facebook page). It actually is not as bad as you think, and it really makes you feel very strong.