Jan,

I found out this year that NSF prefers that one institution takes the lead on
such a collaboration.  I have one active account and one recent submission in
which another school was involved as a collaborator.  The proposal was
submitted with the Co-PI's on the cover sheet and both signatures on the
signature page.  When awarded, Lehigh negotiates a subcontract with the
collaborating institution.

I have heard of a situation where a single proposal was submitted with a cover
sheet from each institution.  When approved, NSF made two awards.  I heard
about this from NSF personnel and they hated it because it was a paperwork
nightmare!  Personally, I can't see any advantage except to avoid doing a
subcontract.  I've never found this difficult when working with other
institutions.  (Industry and DOD labs are another matter!!).

Good luck,

Ruth Tallman
Office of Research and Sponsored Programs
Lehigh University
526 Brodhead Ave.
Bethlehem, PA  18015
Phone: 610-758-3024
E-Mail: xxxxxx@lehigh.edu