I have some projects in Excel (worksheet formulas+VBA) that I would
like to protect them as much as possible. Of course, my customer has
to be able to open it and work with it. I know that the solution will
probably be weak, but I just want the best I can get... I'm using the
VBA Project password, that's as far as I could go. By the way, how
weak is it? (i.e., if the guy has to use a password cracker that takes
more than 2 days I would be happy with it :)

Also, is there a third party security software that could help me with
that?