I put up a post about different bodyweight exercises that can replace some of your traditional exercises. I am a big fan of body weight exercises and use them all the time in my workouts. One reason I like them so much is because you are moving your body, not moving a weight. It is much bettter to mover your body than it is to move a stack of weights.
If any of these become too easy you can always add a weight vest or some other kind of load.
Click Here --> Bodyweight Exercises