The eyeballing game http://woodgears.ca/eyeball/index.html?
the first 10 million digits of the square root of 2 http://antwrp.gsfc.nasa.gov/htmltest/gifcity/sqrt2.10mil
Color Test http://www.humorsphere.com/fun/8787/colortest.swf
Two Centuries On, a Cryptologist Cracks a Presidential Code http://online.wsj.com/article/SB124648494429082661.html
Rubik's Cube finally solved after 26 years by avid fan http://www.telegraph.co.uk/news/newstopics/howaboutthat/4217732/Rubiks-Cube-finally-solved-after-26-years-by-avid-fan.html
Pew News IQ Score http://pewresearch.org/newsiq/quiz/index.php
This is a special intelligence test for Trolls; it will not work for normal human beings http://www.flayme.com/troll/quiz.shtml
140-year-old math problem solved by researcher http://www.eurekalert.org/pub_releases/2008-03/icl-1yo030308.php
The World`s 10 Most Famous Uncracked Codes http://historycus.blogspot.com/2007/10/worlds-10-ancient-uncracked-codes.html

Can you crack the famous unsolved Zodiac 340-character cipher? http://oranchak.com/zodiac/webtoy/
Maze Generator http://www.xefer.com/maze-generator
What's this fuss about true randomness? http://www.random.org/
Play Chess Against the Computer http://www.chess.com/play/computer.html
Tom Lehrer performing at a Maths lecture, some of the only footage of him anywhere on the internet!!! http://www.archive.org/details/lehrer
IQ test (flash) - You have 40 minutes to answer 39 questions. http://www.iqtest.dk/main.swf
Sudoku Generator http://www.opensky.ca/~jdhildeb/software/sudokugen/
Daily SuDoku! http://www.dailysudoku.co.uk/sudoku/index.shtml
HL2 Rube Goldberg http://video.google.com/videoplay?docid=8926325136071596338&q=