Hello everyone,
I just wanted to add that Opera supports spell checking in input boxes by
using GNU Aspell. You just have to install Aspell plus the languages you
need (for Windows see
http://aspell.net/win32/) and restart Opera.
But I have to add, that - in my opinion - aspell isn't a good spell
checking engine and the dictionaries are very incomplete.
Sincerely
Christian Thiele