What's the narrowest runway you've ever used?

http://www.airnav.com/airport/L53

Lodi Airpark near Sacramento, CA has an 1875x22ft. runway. If I remember
right there's a ditch on the side too - leaving little room for error.

Also, Harris Ranch (also in CA) has a 30ft. runway which can be really
challenging because in summer afternoons the wind tends to gust straight
across the runway.

http://www.airnav.com/airport/3O8

- Ray