>Does anyone know of public domain dictionaries of common words? I want to add a spell check function to some Web Connection Applications, so I'm not looking for a 3rd party product based on a Windows UI. I don't want licensing issues, should I decide to deploy any of these apps as vertical market web server products.

You might have luck searching the hacking sites. A lot of them have wordlists that could easily double for a dictionary. For example:

http://chat.home.ru/homes/wordlist/


HTH