@spectreman: I agree with the "just do something anything thing." Get off your butt, adjust your workouts to your age and physical condition, and do something. I get bored in gyms sometimes and have found activities like being active in sports is much more enjoyable. I incorporate boxing and swimming and tennis and walking/running/sprinting in my workouts.
Agreed. For example, I sometimes get bored w/my elliptical, my primary cardio machine. So I'll infrequently hop on my bicycle and go for a ride, or slip on the sneaks and go for a couple mile easy jog.
I also often change my lifting routines so neither I, nor my body, gets bored. Sometimes that as simple as increasing/decreasing weights, reps, mixing up push/pull exercises, doing whole body one day, anything to shock the body.
The boredom from routinization can be a workout killer.