Nancy, good for you: something IS better than nothing!
Kayley -- that's a lot of minutes, and it sounds like your job affords you a chance to work up a sweat. Do you have any exercise goals you'd like to set for yourself in addition to work? Something that work doesn't give you a chance to do, for instance?
Yesterday I did 60 minutes at the gym--30 minutes on the treadmill and 30 minutes of strength training. I'm not going to the gym today because I have to work, but I'll make up for it during the week by staying longer.