Needed to pin this website so I don't risk forgetting it! Fantastic games, mad libs, interactive readings, and other activities suitable for elementary students and various subject areas. So fantastic!
Houghton Mifflin (the education textbook publisher) sponsors this website that helps kids learn parts of speech - nouns, adverbs, adjectives, verbs, etc. Using interactive stories called "Wacky Web Tales" they offer an online version of the classic car game, Mad Libs.