I've been developing on a tool for working with files in the BIFs.
Right now, you can:
*extract an entire BIF or individual files
*view/edit/save non-compiled scripts (nss)
*open, view, edit and save 2DA v2.b (2D Array) files
All from a windows application.
2DA file support allows you to either load a file on disk that you previously extracted or get it direct-from-BIF, edit it in a grid-based GUI, then write it out to your override folder.
I've been able to leave the tool up between Kotor launches, so I can make a few changes, run Kotor, see the effect, quit... lather, rinse, repeat...
I plan to add support for the other file formats as I figure them out; some are pretty scary
Once I find a spot to host my app, I'll put it up.