Howl, your a much better person than I! I used to have a commute that has about a 1 km walk on each end, or a bus if I got lucky. I'd probably get lucky about 1.5 times in 4 ... but still got over 2 km of walking every day.
Now I have a much shorter commute but it only has about a 150 m walk on each end ... and it's apparent my level of fitness has dropped, and I've put on a few pounds (not as bad as when I just walked 10 m to the car every day!)!
I know I should change my pattern and add a longer walk to my commute ... but it only ever happens when there's streetcar problems, and it becomes quicker to walk further.