5 links
iVocabulary.com
ivocabulary.com
Offers tests to build students' vocabularies, as practice for the SAT, or for ESL students. Difficulty increases with each correct answer.
Vocab Test.com
vocabtest.com
A series of interactive tests designed to help students learn standard SAT words.
Vocabulary Drill for Kids
edu4kids.com
Uses one less familiar word in a sentence, then provides three possible definitions. Kids use sentence context to choose the correct meaning.