Kendoku

Kendoku is a combination of KenKen and Sudoku

On the sudexel forum you find this variation

'Kenduko Ninjo Links'

http://sudexel.com/forum/

You have to register to get access to the puzzles

KenKen

On timesonline you can find this 'new' logic puzzle

http://entertainment.timesonline.co.uk/tol/sitesearch.do?sortBy=relevancy&offset=0&query=kenken&hitsperpage=25&nextOffset=0&sectionId=1022

KrazyDad's Slitherlinks

On http://www.krazydad.com/puzzles.php you find sudoku's , kakuro's, Jigoku's, Kidoku's, Mazes and Slitherlinks
You also find nice slitherlink-variations on this site: Penrose , Altair, Laves and Snowflake