Rooting learning sites?
the scan of the month challenge: http://www.honeynet.org/misc/chall.html
and for "hacking in the box" application hacking: http://proxy.11a.nu/my-papers-articles/practice-environments-for-ethical-hacking/
z3ro wrote: www.pulltheplug.org
netfish already mentioned that one ;)
I believe the kid is looking for more serious wargames…
Don't get the impression that those challenges mentioned above will not teach you blackhat knowledge. They will teach you some arcane shit, but it's up to you to use it in a blackhat manner, or use it in a more ethical and conservative manner.
http://learnsecurityonline.com/
They have some kickass rooting challenges everynow and then, just subscribe to their mailing list and get updates on when they have competitions. I was too drunk to participate in the last one they had this weekend. Damn that tequila and grey goose!