When driving, at each stop light, suck in your entire stomach to your core and hold until the light turns green.
After doing your business in the bathroom (whatever that may be -ewwww), do ten-fifteen lunges for each leg.
Walk, walk walk! Walk whenever possible. Instead of talking the elevator, walk up and down the stairs. Park in the furthest spot possibly in the parking lot, and walk. Every little bit helps!
I'd love to hear some of your secret exercise tips. When do you make time for your mini undercover workouts?