It takes more concentration to keep your balance. Exercise balls are available at many major sporting goods stores. Strike up conversations. You may develop some new friendships, which will also make you want to go to the gym. Lift by the tube.
Most gyms now have TV's installed in their aerobic training areas.
Crank up the tunes. Listen to upbeat music to stay motivated. There are lots of compilation dance CDs available today. Save money and buy them used. Make sure that they are not defective or scratched before laying any money down.