These wordlists came from the National Puzzlers' League, which I
learned about via Paul Kube of UCSD. You can find details about these
lists and others from http://www.puzzlers.org/secure/wordlists/dictinfo.html


The two that seemed most useful for a Boggle game I put here are the
Official Scrabble Player's Dictionary (~79,000 words) and the "Enable"
word list (~172,000).  Both have a large variety of fairly common
words, including plurals and tensed forms. The OSPD only has words of
up to 8 letters. The Enable list is a superset of OSPD that adds many
longer words.

Given the memory capabilities of today's machines, it is feasible to
do lookups via binary search across arrays of strings.  If you're
interested in the hairy compact directed-acyclic-word-graph
representation we use at Stanford, drop me an email and I can tell you
more about it.