I am interested in Thrift's mention of "the environment [that] acts as a prosthesis which offers cognitive assistance on a routine basis"and how that relates to imagined spaces. Clearly, the mobile device (iPhone, etc) and its accompanying communications infrastructure is a prototypical prosthesis (or host for prosthetic software agents) and embodies all the aspects of 'qualcation' Thrift describes. However, that a large part of devices' sensing capability depends on connectivity implies an interesting spatial coupling between those geophysical locations where information spaces (social networks, Wikipedia, maps marked with the current 'address') can be accessed/calculated and those that are off the grid ('grid' overlapping the traditional sense and Thrift's sense of the word). So the environment comprises a pseuso-geophysical territory that has a topology of potential calculations.
I think that this is relevant when Thrift talks about the "perceptual labour" by which we act as an "instrument of seeing, rather than as an observer" as there are border regions at which we have to transition between two regions of disparate connectivity. In instrument mode, the human is compelled to act as a mediator for calculation, performing the functions of reporting her location, taking pictures, and generating demand for bandwidth (eg, I'm writing this on a wifi-enabled bus). This increases the potential for calculation at that physical place or vector, in some sense recuperating it for the grid. There is undoubtedly a strong cultural volition to expand the calculating territory as the imagined worlds enabled by calculation and inhabited by the highly-connected elite are frustrated at the borders.
This might be over-simplifying things, but that expansion seems like it's roughly analogous to the degree of despatialization discussed by Appadurai. For example, in regard to images, I think it would be reasonable to claim that the calculating territory cannot produce its own images of the world -- it can only reproduce them (and even depends on their supply via the perceptual labor of its users). Therefore, I wonder if the depth of the potential for calculation in a place then has an inverse relationship with the time it takes for the cultural recursion that Appadurai discusses to happen (from decades to milliseconds). The shorter the access time (to exchange with the "synchronic warehouse of cultural scenarios"), the less temporally bound the individual, and the greater the consequent effects of despatialization.