While I’m over at Crooked Timber, Eszter Hargittai recently had an interesting post on disciplinary boundaries and some of the difficulties of doing interdisciplinary work. Henry Farrell follows up with, among other things, a very insightful extended quote from Susanne Lohmann and from a follow-on post from physicist Cosma Shalizi. See also MeshForum for more networking on social networks.
I think universities are not very good at providing incentives and evaluation to make good interdisciplinary work happen, for many of the reasons that Lohmann cites. This is too bad, because I think interdisciplinary boundaries are where a lot of the most fruitful ideas are currently found.