This is a very effective applet that shows the effect on the vector cross product when the angle between the vectors or the magnitude of the vectors changes. You can rotate the plane in 3-D to look at it from any angle. It was last revised in 1996! Just goes to show that good ideas (like good men and women) age well.

http://www.phy.syr.edu/courses/java-suite/crosspro.html

Change the magnitude and direction of a vector to try to hit the stationary cyclone.
http://illuminations.nctm.org/ActivityDetail.aspx?ID=42

The previous activity was just a warm-up for this activity, where you try to hit the moving cyclone.
http://illuminations.nctm.org/ActivityDetail.aspx?ID=130

Now it is getting interesting! In this activity, the students have to control both the velocity of a plane plus the velocity of the wind to catch the cyclone.
http://illuminations.nctm.org/ActivityDetail.aspx?ID=43

A neat Geogebra applet to interactively illustrate vector addition. From The Lawrenceville School Math Department Website.
http://mathplotter.lawrenceville.org/mathplotter/mathPage/vectors.htm