First 20 challenges (all)

Level 1. Make a nasa.gov URL display a text of my choice
Level 2. debfKNH1AvtBo deGH9Aq./kiSY denjFRfA8kzL2
Level 3. Recognize
Level 4. IP address is 72.14.221.104. What contains 'art' that points to it?
Level 5. Password is the owl's name
Level 6. Let's see you do some easy SQL ninjitsu
Level 7. snifflog.txt - ngrep format
Level 8. Password is on a picture: not available from anywhere
Level 9. Elementary Maths
Level 10. A poem
Level 11. As simple as hashing a string
Level 12. Ultra Turing
Level 13. PHP with source - needs exploiting and/or o-o-t-b thinking
Level 14. Recognize #2
Level 15. download.com's uptime
Level 16. root:hsmfs;g@10.0.0.5
Level 17. Feed me!
Level 18. Find all usernames
Level 19. red+blue+green = ?
Level 20. Recognize #3

Top 10 : 1. PxL (50)   2. c0d (50)   3. fry (50)   4. gondil (50)   5. deaden (50)   6. m00 (50)   7. shinnok (50)   8. phoenix (50)   9. Reaper (50)   10. Hamstah (50)