I work part time from home and so during nap time and bedtime I'm on the computer. I had to find something to fit in while 2.5 DD is awake. What has been working for me is biking. DD does not like to sit still, so stroller walks aren't for us. DD knows that somewhere along the biking route we'll stop at a playground for a little while and that seems to help. I originally had a bike seat added on to the back of my bike, but I found it a hassle. Too difficult to balance the bike while loading/unloading the toddler. I recently got a bike trailer and it's working out better. On the pro side, she gets to play with toys along the way and it is also safer (not as far to fall should it tip over). On the con side though is that it is a lot more work for me as the biker, but hey, it's exercise, right? I get from 30-45 minutes a day and am really enjoying it.
Plus, on the days you are riding by yourself you feel like such an athlete because you're going so fast with no trailer to lug!