One can
easily imagine the chaos is these two dictionaries are applied
simultaneously in a spellcheck operation on the same message.
I was thinking more along these lines: if a word is found in either
or two dictionaries (en_us, en_gb) then it is to be taken as having
been spelled correctly. If I intersperse French words in an
English language e-mail, and I don't want them to show up as
misspellings, then I should have that option.
The latter is what macs do, and speaking as someone who uses 3-4
languages daily, sometimes within the same message, is what works.
(it's even convenient to switch keyboard entry on the fly, for code
or for colleagues)
The polar opposite seems to be Windows Mobile, which seems to require
two screens worth of dialogs each time I switch languages, and has
its interface language hardwired.
-Dave