https://www.youtube.com/watch?v=xUHQ2ybTejU&feature=youtube_gdata_player
The example of a surface which we have seen in the first lecture: Möbius Strip.
Please see the videos
http://www.youtube.com/watch?v=JNtKcK27x1s
http://www.youtube.com/watch?v=Eb-Fi8GI6PE&feature=related
You can also visit
http://www.dimensions-math.org/
Frenet Frame moving on a helix:
http://upload.wikimedia.org/wikipedia/commons/8/87/Frenetframehelix.gif
Frenet Frame moving on a special curve:
http://upload.wikimedia.org/wikipedia/en/0/07/Triedro-frenet.gif
Curvature and torsion:
http://upload.wikimedia.org/wikipedia/commons/7/70/Torus-Knot_nebeneinander_animated.gif
The adventures of the Klein bottle:
http://www.youtube.com/watch?v=sRTKSzAOBr4