In these days I am looking for a method to log the interactions of users of ubiquitous systems, namely the exchange of SMS and the influence of location on those exchanges. The current methodology adapted from Grinter and Eldridge is very basic but effective. Somehow I am trying to enhance this with an easier location logging techniques.
I had in mind this idea of providing a separate map to the observed participants but how do people should carry around the logging sheet and the map? It seems a bit inappropriate to ask them to have all this material floating around in their pocket or backpack. The big risk is that they will loose it with the contained information.
So I had an idea combining an intuition of Nicolas and a solution found in a book of 1906! First of all, as Nicolas noted, the log material should be pocket size in the form factor of a sketch book. A single page can be assigned to a single SMS, leaving the annotation much more compact than on a letter-page.
The second intuition, suggested by the book , is that a foldable map should be attached to this small log-book, in such a way that could be unfolded when annotating an folded back when moving around. The participant will use the small log-book to register incoming and outgoing SMS, annotating extra information like time, motivation to the communication, content, length, etc. Additionally, using the foldable map it will be possible to indicate his/her position at the moment of reception and the inferred position of the recipient/sender of the message.
Below are the pictures of the book which inspired this solution. In the extended part of this post, I will report some more research I did on how to fold a map.
 Karl Baedeker. Italy: Handbook for Travellers, First Part, Northern Italy. Karl Baedeker Publisher, Liepsic, 1906.
Research can be fun sometimes. I found this bunch of Researcher writing papers on how to fold a map. Apparently, there are a couple of mathematical algorithms behind:
 Arkin, E.M., et al. Preprint. When can you fold a map? Available at http://xxx.lanl.gov/abs/cs.CG/0011026.
 Gardner, M. 1983. The combinatorics of paper folding. In Wheels, Life and Other Mathematical Amusements. New York: W.H. Freeman.
 Peterson, I. 2000. Proof clarifies a map-folding problem. Science News 158(Dec. 23&30):406.
Out of this huge quantity of mathematical papers I managed to find a nice guide that shows visually three solutions for folding a map. I report below the two visual guides.