One of the games that I am thinking of doing is a small puzzle game that tests a players spelling ability. I've noticed a few other word games about, and I was wondering where the dictionaries for these games come from. For those of you who have done games of this type:

Do you create your own dictionaries, or do you acquire them from third parties?

If you create your own, how do you go about it?

If you acquire your dictionaries, where do you get them from?

Do you know of any free dictionaries around that are highly comprehensive?

cheers

John