I don't know if anyone's seen this already: Princeton's Cognitive Science Lab has been developing a very nice project called WordNet: http://www.cogsci.princeton.edu/~wn/ It's an extremely nice dictionary-like program that also shows relations between words. Python bindings for WordNet have been written here: http://www.cs.brandeis.edu/~steele/sources/wordnet-python.html What interests me about it is that it lets me play around with words effortlessly, and it's definitely one of the tools that I regularly use. It would be interesting to see if WordNet could be used in a CP4E curriculum --- it would offer a change of pace from doing "mathy" stuff, and it would allow students to explore a natural language with a computer language.