These online Futoshiki Puzzles were created by KrazyDad (you can find puzzles of all types on his site here). The puzzles are similar to Sudoku and KenKen in that you are trying to place numbers in a matrix using logic without repeating digits in any row or column. The twist is that Futoshiki puzzles provide clues using the inequality symbols for less than/greater than. Your clues are in comparing boxes that are on either side of the inequality to determine which digits would logically work.
Jim Bumgardner, the man behind KrazyDad, provides practically unlimited puzzle game fun on his site, so once you get worn out on the Futoshiki puzzles I recommend you try some of his other unique puzzles.