Hi George,
I'm sure there is... but I had to have my host do all the Aspell config for me so I doubt I could easily "add" words.
As a work a round I am using IESpell for Internet Explorer and SpellBound for Foxfire.
Pros
Both allow the addition of your own words and a choice of languages.
Cons
These programs have to be installed on your local machine and are user dependant.
Hope this helps.
Jeff