Thanks for casting the net on this, Maha!
The AMICAL Consortium has been thinking of doing something like these ‘want ads’ for a while, though for internal use among faculty and staff at member institutions of our consortium. One form of this idea was to create profiles advertising expertise, interest/willingness to collaborate, and need for collaborators, while providing mechanisms for indicating (& finding) disciplinary focus, specific methods or technologies for research/pedagogy, technical or professional skills/experience, etc.
Rebecca’s comment makes me wonder, though, if it might be interesting to make part or all of AMICAL’s scholarly/professional ‘personals’ open to the world, or at least to external colleagues interested in networking with members of our consortium.
And the idea of thinking in terms of ‘want ads’ instead of ‘profiles’ may be useful itself — keeping the system simple, less structured and with fewer requirements might actually be the key to getting people to actually use it!