For the puzzle challengers in you!!

if you want an challenging web site check out
http://www.readymech.com/ it gives you puzzles to print out and put together.

check it out on a computer near you.

http://www.spotthedifference.com/ is another website for the challenging mind. It shows you two pictures and you have to spot the differences.
Complete the level and move to the next one to the unknown universe.

Both these websites are challenging check them out!