Some new information has just scuttled across my desk!
It seems that there is in fact a type of social spider, and a recent paper in the Proceedings of the Royal Society has looked at the role of social interaction amongst these creatures (Stegodyphus Mimosarum).
http://www.the-scientist.com/?articles.view/articleNo/39577/title/Behavior-Brief/
This is all very well, but has someone counted these spiders up and ascertained if the counts fit a Poisson distribution (e.g. are these spiders Poisson-ous (!!!), or some other distribution, (and what are their views on competing sundew plants?)
Laskowski KL, Pruitt JN (March, 2014). Evidence of social niche construction: persistent and repeated social interactions generate stronger personalities in a social spider. Proc Royal Society B.