People in the developing world have cellular handsets but very little money. If you wanted to get information to these people, they are highly unlikely to pay the GPRS/3G costs to access it.
In the previous Big Board project we built a system using a PC and LCD screen that allowed users to download and upload material to a shared server over Bluetooth.
However, PCs and screens are expensive and need electricity, which limit their applicability in developing regions. To solve this, Graeme has ported the Big Board code to a Windows Mobile handset so it can act as a server. Rather than use a screen, we now use printed images. The code has been ported and we are now testing various use-cases (such as in a taxi)