It's ACT/MME test week, so the schedule is a mess. I used yesterday/today to give students more time to finish the trapezoid & kite investigation in Geometer's Sketchpad.
Sketchpad is an amazing piece of software, but it's not terribly intuitive or user-friendly, especially dealing with high school students that aren't especially tech-savvy. As hard as I try to write directions that are clear and explicit, many students become frustrated and give up before reaching final conclusions.
The focus of the activity was to help encourage the need to empirical evidence to justify conclusions. Rather than use a ruler and protractor to make measurements, we can use the computer to do the hard work for us, but we still need something to back up a statement like "the diagonals of a kite are perpendicular."
Moving forward, I've begun to use Geogebra in place of GSP. Very similar functionality, but 1) Geogebra is free, and therefore can easily be installed on the school's computers, 2) Geogebra has a much more intuitive interface (IMHO). I've also begin thinking about interactive java applets I can make and upload to my class website for student exploration while at home. I know you can do that with GSP, but I lack the most recent version, so I was having difficulties getting it done.