Each group of students was assigned to one set of words and worked together to group them. They looked for all kinds of relationships: synonyms, antonyms, related adjectives and nouns, words with varying intensities, etc. Some groups devised ways to position words to show relationships (for example side-by-side for synonyms and perpendicular for antonyms).
After about ten minutes working with their own set of words, the groups set about grouping all words.
Granted, not all of their work was perfect, but it was a perfect (and quick) way to review sets of related words and employ higher order thinking skills.
We had a blast! I plan to use this activity again and again.
P.S. If you're looking for a great way to review vocabulary on the computer, check out Quizlet!