I remember when I moved to California being surprised that leaves and grass clippings were "cleared" using what we called leaf blowers. If you happen to live in an enlightened area where people still clean up their leaves with a rake or a mulching lawnmower, a leaf blower is a two cycle engine that blows a high volume of air out a wand that the operator uses to move leaves around. They're incredibly noisy (50 feet away they're about 100 times louder than World Heath Organization recommendations for outdoor sound levels), and cause an unbelievable amount of air pollution (up to seventeen times the amount a modern automobile produces).1
Recently, I had the same surprise on campus when Facilities Services at UAF started equipping their sidewalk cleaners with the same devices, except now they're using them to blow snow. I don't have the data to perform an economic analysis of this decision, but I guarantee that when you add in the externalities of noise and air pollution, engine maintenance, the damage done to cars when they blow gravel into them, and the impact of burning fossil fuels on the global climate, a shovel starts looking pretty cheap.
They also don't do a very good job because they can't remove snow that's been packed down at all. Check out all the footprints in the image. I can't help but wonder, once again, if some problems are better solved with less modern technology.
1These figures come from a variety of sources, referenced on this site. It's a biased site, but I trust the cited sources.