I think it could be dangerous to think too much about appearance
at this point. File input is clearly useful for a number of reasons
so it seems reasonable to make it a special type of form input.
Wedging it into the TEXTAREA input sounds like trouble.
I'd like to suggest 2 more requirements-
* allow the user to submit an arbitrary number of files
* preservation of the original file name, when possible
Imagine you want to provide access to a c++ compiler
or something odd like that via www.
-- firstname.lastname@example.org -- http://netlib2.cs.utk.edu/people/ReedWade.html