much better videos are to come!
Having Fun Dunking

Not bad... but you should raise the hoop up a little bit. Work on your hops (lots of jump rope, calf raises, squats, lunges) and push yourself so it isn't so easy...
If you keep the hoop low like this, then you won't aspire to jump higher. I'd keep it at the "up a notch" height at the very least... if not even higher than that.
This is coming from a 6'9" former college basketball player, it isn't just blowing smoke!
Here is a video of me, my brother, and my friend dunking a basketball.
http://www.youtube.com/watch?v=rQYz6H2s6_g
Enjoy!