Check out this site for a Linux Reverse Engineering Challenge.

http://www.hackerchallenge.org

HeX

sounds interesting, but i guess that levels are quite hard for such prizemoney.

EDIT: It's ok I received the files.

sounds nice,

thanks for the tip

i subscribed

ps: what i dont like is the "who is fastest approach". not everybody might have the same amount of uninterrupted free time else, its cool