It's been at least a year since somebody has mentioned David Peterson's bicycle snow plow.

Peterson rides his bike seven miles to his job at Fermilab in Chicago Chicagoland. When he built this snow plow for his bicycle several years ago, the bike paths he took to work weren't plowed, so he started walking to work with a shovel and shoveling the path along the way. He soon moved up to a push plow, a contraption he pushes like a baby stroller with angled blades to push the snow to the side.
In 2002, he built his tow-behind snow plow.

David Peterson posts the history and detailed construction plans for the bicycle snow plow
at his website. I have no idea if he still uses this (the website was last updated in 2005), but I've sent Peterson an email and we'll see what he says.
Here's another bicycle snow plow photo I found randomly on the web.
Read the complete post at http://feeds.feedburner.com/~r/Cyclelicious/~3/223743783/bicycle-snow-plow.html