Digital wireless communities have existed since the days of amateur packet radio (ham radio), in three well-defined categories:
These three categories are well established, and well known in the ham radio (amateur radio) digital wireless communities. Of particular interest are the latter two categories (Mobile and Portable) because they have been made possible by miniaturization of components.
Category 2 (Mobile) is described in KA6WKE's web site which describes how to deal with the less than optimal antennas and grounding systems of mobile units (within a 1992 Ford Escort station wagon, being a small car, that presents many such challenges).
Good examples of mobile wireless digital radios include the HF Mobile Rig - FT-100 and various two meter mobile rigs.
Portable (worn or carried) rigs are described in N1NLF's sites, http://wearcam.org and http://eyetap.org.
Portable rigs are often known as ``handie talkies'', and, together with a Terminal Node Controller (TNC) provide portable wireless data connectivity. More recently, various other devices provide similar connectivity, without the need for a radio license. Such systems include cellular phones, pagers, and digital cameras with wireless communications. These systems fall under category 3 (Portable), thanks to modern miniaturization. With a 12 volt cigarrette lighter adapter, they may be operated in Category 2 (Mobile), and often come with a wall plug adapter for operation in Categoery 1 (Fixed). Most digital cameras have a standard ``1/4, 20'' threaded hole, to accept a tripod mount, so that they can operate in Category 1 (Fixed) mode.
The recent explosion of license-free low power radio systems makes possible a new form of community across all three categories. Fixed or Mobile ports on homes, and cars, can also serve as gateways for a community of portable logging systems. With no central authority able to ``pull the plug'', such systems may give us that which the Internet promised but failed to deliver: truly decentralized communities.