Thanks everybody for comments, although I guess the use goes so far back into antiquity that the request for an original reference is unanswerable. For context, with two young collaborators (Bertrand Guillou and Mona Merling), I have a draft in progress tentatively entitled ``Chaotic categories and equivariant classifying spaces''. I prefer `chaotic' to `indiscrete' not just because of the `coarse' implications of the latter, but because indiscrete spaces are boring, `null or banal', whereas chaotic categories have genuinely significant applications. They are quite surprisingly central to the theory of universal bundles, equivariant or not. Via the (product-preserving) classifying space construction from categories (especially categories internal to spaces) to spaces, they provide a rich source of contractible spaces that can very easily be given interesting additional structure. That is just what one wants when constructing universal bundles. More fun, it is just what one wants to construct an E infinity operad of G-categories that defines `genuine' symmetric monoidal G-categories (which are not merely symmetric monoidal categories on which a group G acts in the obvious `naive' way). These which give rise to `genuine' G-spectra. Genuine G-spectra that define equivariant algebraic K-theory arise in precisely this way. All starting from chaotic trivialities. Cheers, Peter [For admin and other information see: http://www.mta.ca/~cat-dist/ ]