In a logical surf from your vids i came on this
http://www.youtube.com/watch?v=rDZllJtBlcM&feature=related

Using a fishing rod appears to be a modern staff sling where the line is attached to the projectile and you reuse the projectile  without walking to get it (while occasionally catching a fish)    

I've often thought that a surf pole would make an excellent staff sling, but instead of using a reel, just hold on to a piece of line that's attached to your projectile.  Cast and let the line go.  With something like a 14' UglyStick you would send a four ounce bank sinker to France.
     Nice vids, timann.  

"With something like a 14' UglyStick three you would send a four ounce bank sinker to France. "

To france ? i'm in Morocco and with that setup i could sling almost to .....China (or at least get close)   

Curious Aardvark wrote on Apr 21^st, 2011 at 12:27pm:

Tkanks.  JR learned the figure8 last year, after practicing simple overarm for some time, and this was his first attempts after the winter.  Unlike his father he do not bother with slinging when it`s cold.

It`s rather uncommon, yes

We was out again, today, but now we slung a tennis ball back and forth across the soccer field.  At distances approximately between 40 and 60 meters its funny and safe.  It`s hard to hit someone at such distances(for us), aiming is hard and the tennis ball is easy to avoid.  
So it`s more like hitting an enemy formation, though you aim for the one with the plume on his helmet

Closer, near 30 meters testing was another story, I found myself rather capable of get the aim stright at my son at this distance, and he had to be really aware to succeed in eluding the tennis ball.

My son`s figure8 was great now, as he had got a bit of practice, and used his favorite sling (worn Apache sling made by his father).
timann