Hi there. I don't know if you're interested in interval workouts, but I often do these workouts, which, due to their intensity, make 30 minutes feel like 90
(in other words, you'll get PLENTY of cardio activity for your day).
run/jog warm up 8-10 minutes, or a mile/1.6 kilometers
400 meters at speedy pace (should be faster than your normal run, but not all out sprint; for me, this is about a 7:00 min/mile or 7:00 min/1.6K
200 meter run at 10 seconds less than what you did your 400m at (eg., 6:50 min/mile/1.6K)
back to jog/run for a couple minutes.
Repeat sequence 4-6 times.
Jog/Run for about 5 minutes at end.
OR
you could do pyramids (either up or down):
400m
800m
1200m
1600m (mile)
after warm-up, do the 400m at a quick (almost sprint) tempo, 800m about 10-20seconds-per-mile slower, and so on...
OR you could do hills - 5-6 hills of 2-3 minutes each at between a 5-10 percent grade.
As you can see, LOTS of variety.
Hope it helps.