I need to be able to allow a browser access to a local filesystem, to be able to pick and note the name of a local data file.

Using the <input type="file", name="new_image"> tag, I can have a browser display a file browser dialog. My problem is that the returned filename may or maynot have the full path (Internet Explorer returns a full pathname, Mozilla returns only a filename). I would like the full filename to work with.

Anyone have any solution that will let me get a fully qualified path to a file, regardless of the browser being used?

I'd say you need to write some java-script to do it.
(I've never used java-script myself though)

OK, if that is the case, has anyone else actually done this (or something similar) with javascript?

You can access form-values in javascript with the variable
form.<field_name>.value

This variable contains the full path entered as desired regardless of the browser used