I'm partial to using a very broad dictionary: http://app.aspell.net/create?max_size=35&spelling=US&max_variant=0&diacritic=strip&special=hacker&special=roman-nu

I'm partial to using a very broad dictionary: http://app.aspell.net/create?max_size=35&spelling=US&max_variant=0&diacritic=strip&special=hacker&special=roman-numerals&download=wordlist&encoding=utf-8&format=inline http://app.aspell.net/create?max_size=35&spelling=US&max_var.... It has 50,105 words. Gets you an extra 2.3 bits per word.