I have a couple of large textfiles of about 259MB (+). Some of these
files need to be edited. I've tried using both emacs and vi but they
both present an error message stating that the files is to large to be
edited.

The method I have used so far is downloading the file to my Windows
worksstation and editing them with Textpad, and then uploading them to
the server again.

Do anyone know of any console editing applications that can handle
editing such large files on Linux/Unix?

Any help is appreciated.
Michael