So I have been looking for a good survey article on Ubicomp Systems for a while, and I finally found one:

Endres, C., Butz, A., and MacWilliams, A. 2005. A survey of software infrastructures and frameworks for ubiquitous computing. Mob. Inf. Syst. 1, 1 (Jan. 2005), 41-80.

This is a great review article, simple, to the point, and pretty complete when it comes to providing information about a lot of Ubicomp systems.  I really wish I had read it about a year ago, but it seems somewhat hard to find.  In any case, it doesn’t provide very much depth on any of the systems, but provides a good place to start when hunting for a framework to use for a Ubicomp project.