http://milwaukee.craigslist.org/spo/816720107.html

i kinda want to make one.

http://www.snowbike.us/

This is legit http://blog.makezine.com/archive/2006/12/snow_bike_kit.html

http://www.snowbike.us/

This is legit http://blog.makezine.com/archive/2006/12/snow_bike_kit.html

How hard is it to get up the hills on one's own power, though?

East Hill

I've never tried one although I'd like too, looks fun.