http://www.learnsecurityonline.com/index.php?option=com_content&task=view&id=293&Itemid=1that was an easy interesting challange, the writeups are also very interesting. thanks to Chris and Dean from LSO for providing such challanges, and following them up with nice writeups and summaries.
if you have not tried the first two, you still have a chance to catch the new ones soon hopefully
Tools : NetWitness Investigator is now free! 
