Stall strips:
http://en.wikipedia.org/wiki/Stall_strips
http://en.wikipedia.org/wiki/Stall_(flight)
http://www.mindspring.com/~cramskill/tamstall.htm
http://selair.selkirk.bc.ca/aerodyna...ols/Page4.html

This should give you the idea of what they are.

Now how about Stall fences?
http://www.centennialofflight.gov/es...ngs/TH20G6.htm
http://www.djaerotech.com/dj_askjd/d...tipstalls.html