I've posted before about exercise being a key to fat loss. With the warm weather, I've begun interval training outdoors again (I just couldn't manage treadmill running over the winter - I was overwhelmed). Running is wonderful for those with little time - you can accomplish a lot, and you get started just by putting on some shoes and heading outdoors.
Even just an easy walk is a great way to start. Work up to 30 minutes of walking, and then start adding in some interval running. Right now (and I'm still just a beginner myself) I do a 5 minute walk to warm up, then I run for 1 minute and walk for 2 minutes for 6 rounds, and then walk for 5 minutes to cool down. That's 28 minutes, 6 of which are running. I'll do that until it begins to be easy, and then I'll adjust the rest time down and increase the rounds, or adjust the running time up. You really can fiddle with it anyway you want, so long as you increase the time you're actually running.
I'll also stay on a 1:2 interval, but push harder during the runs - I'll try sprinting for a minute, or at least going faster.
Within the next couple of months, I plan to head back to the gym and start lifting weights again, but for now, I'm just creating a routine of starting the day with exercise. That will help keep the weight off long term.