Hey there, I am writting this article hoping that i am gonna get sleepy while i am doing it:P.
anyway, i will give u some tips to help you solving the 1st scenario in the hack me contest,which i think its much fun, and no solving this scenario wont make you a legend hacker, not even a scum hacker:P.
now lets use some brains cells, consider this sql statement,
-->select whtever from whtever table where username='someone name' and password='his password',
now all what this scenario talking about is something called sql injection, and yea it hurts:D.
lets look at another sql statement..select hottest_girls from hot_girls_table where hair_color='blond' or wight='50kg'
now that girl should be hot, cuz she is going to be a blond or look like a model and both are hot,what if i said this    
-->select hottest_girls from hot_girls_table where hair_color='blond' and wight='50kg'..now i want the girl to be blond and weight 50kg, this time i put 2  conditions, with [or] i told the database that i am not picky, i just want a girl that is blond or weights 50kg, but when i used [and], i was more picky, so now, try not to be picky, and inject the [or] inside the password field, it should be easy to be solved right now, and no i am not sleepy since i started talking about hot girls:D, now i am going to watch some videos while you are trying to inject some stuffs in other stuffs.

peace.