I walk every morning for 30 minutes and ride my bike three days a week for about 50 minutes or so.
I go to the gym and use the elliptical, treadmill, rowing machine and also those moving stairs. Those are horrendous but bring the heart rate up super fast. If you can find them give them a try or just try walking up a lot of flights of stairs at the mall or in a building. The Empire State Building has 86 flights so keep track of the flights you climb and when you hit 86, you can claim to have climbed the Empire State Building. Then pick another building. Great cardio workout.
I run three days a week and then do low impact cardio three days a week after weight training.