http://www.manythings.org
(Word games, puzzles, quizzes, exercises, slang, proverbs)

http://a4esl.org
(activities for students in multiple languages)

http://iteslj.org/links
(The TESL Journal online)

Martindale's Language and Translation Center (many, many, many languages)
http://www.martindalecenter.com/Language.html

Free Online Language Courses (118 languages!)
http://www.word2word.com/coursead.html

Languages Online (French, German, Spanish and Italian)
http://atschooleduweb.co.uk/rgshiwyc/school/curric/HotPotatoes/Menu.htm

Spanish
http://www.kn.pacbell.com/wired/espanol

Hotlist of Language arts sites to use in ESL
http://www.larryferlazzo.com

English-Spanish Vocabulary Quizzes - more adult
http://iteslj.org/v/s