I thought I read somewhere that Carter Aviation has used depleted uranium in the blade tips in their 500mph high-tech autogyro (the pic on their home page at the top) to take advantage of the inertia... not sure if they used it in the small gyro in these videos, however. If the jump takeoff displayed in the videos is a true jump takeoff (as in setting the blade pitch to zero or neutral, over-revving the rotor, disengaging power and then making a collective blade pitch change to make the jump) then based on the altitude achieved there's a good chance they've got lead or depleted uranium in them thar blade tips.

Here's Carter's explanation of a jump takeoff: http://www.cartercopters.com/faq-gen...tml#question8b

Here's a good pic of the rotor used on the ultra-light autogyro in the videos: http://www.cartercopters.com/images/...ight_rotor.jpg

Note the configuration of the blade tip. The stuff they're doing is high tech, for sure.

This link may have been posted previously somewhere on this forum, but I'll share it again here. In addition to the highlights of their Carter Copter and the PAV 2+2, there's a Pitcairn PA-36 "Whirlwing" performing a jump takeoff in 1939 at the end.
http://www.cartercopters.com/highlight_video.html

One other note about Carter Aviation, they reached a milestone in rotary wing history on June 17, 2005 with their Carter Copter. Their aircraft's forward speed exceeded the tip speed of the rotorblade (relative to the aircraft) in forward flight. (I think I explained that correctly. See their FAQ page for more detail.) That had never been done before. They did it by slowing down the rotor rpm and allowing the small wing to provide the lift necessary for maintaining flight at high speeds.

Their website has some really cool pics, videos and info if you've got some time to browse around.