For those of you who can't seem to get enough of challenging puzzles, check out the
Google Puzzle Championship. Questions run the gamut from math problems (like the Japanese Sudoku puzzle which has taken much of the world by storm) to word problems to testing your eye for detail. A practice test is available
here, or you may view the 2004 test
here. Full rules may be found
here.
If you are lucky (or skilled) enough to be one of the top two United States contestants, you will be invited to represent the U.S. Team this October at the World Puzzle Championship in Hungary. Good luck! Last year
devjoe from the ARG community placed third in the Google challenge and went to the championship in Croatia, where the U.S. team took first prize.