I can't imagine actually using this, but I love the ingenuity.
When I was a kid we had a smallish yard and a push mower. The smallness of the yard did not in any way make me any more willing to mow the lawn on the fairly rare occasion that I was asked to. A mower like this might have done so. Here is a pic of the bike in action (links to a page with a video).
At any rate it beats this style.