GeoGebraTube applets:

Hyperbolic Geometry
This applet uses GeoGebra in the web browser with added tools for exploring geometry in the Poincare Disk, or hyperbolic plane. This applet is interesting to me because I've had very little experience with non-Euclidian geometry, but I find it intriguing and I think high school students could find it interesting and exciting as well.

Transformations in Parametric Form
This applet allows students to change the constants associated with x=acos(t)+b and y=csin(t)+d to see how these affect the shape of the parametrized curve in cartesian coordinates. This applet is interesting to me right now because I work at the math tutor lab and the students in calc II are learning parametrizations. I never realized what an interesting and hard to explain topic it really is! I think this applet provides a visual and intuitive approach to parametrized curves.

Related Rates Rocket
This simple applet shows how the height of a rocket relates to angle from a camera on the ground, and how the change in height (velocity) relates to the change in the angle. I like this applet because of its simplicity. Related rates are hard for a lot of students, and I think a simple example like this can help visualize why related rates work and what they are.

Sine and Cosine Components
This applet shows the unit circle and the sine and cosine values at any given angle. I would use it in my classroom for showing why arcsin and arccos return two different angles, as well as using it in tandem with a cartesian graph of sin and cos, to show how the unit circle relates to the cartesian graph. This applet is interesting to me becasue I LOVE TRIG!!!

What's special about e?
This applet is a simple grapher for exponential functions and their derivatives at any given x value. I find this applet interesting because it is very usable for a variety of objectives and lesson plans, even for the lesson we are going to give to our math ed peeps in class today!