Hide it with a towel. Work out to music. Look at the clock only after every song. (OK to peek during long songs).
Hide it with a magazine. Look only when you are done reading the magazine.
When you are done reading the magazine, use it to hide two-thirds of the reader information at a time. Allow yourself to look at the distance/mileage/clock only once you have achieved a nice round number (50 calories, 1 mile, 5 minutes) from the previous counter.
Hide the counter with a towel or magazine. Watch a sporting event. Look at the clock only during half-innings, time-outs or when the sporting event clock is at a nice round number.
Hide the counter with a towel or a magazine. Watch TV. Look at the clock only during commercials.
Hide the counter with a towel or magazine. Watch "The Today Show." Look at the clock only when the home-town clock in the corner of the screen reads a nice round number.
Skip going to the gym; find a better way to channel somewhat questionable compulsory tendencies.