It's Place, Not Space
Indeed, space is just a gateway to place: we need the coordinates to compare to other coordinates, but what we care about is proximity.
The good news is that while for now the coordinate technologies like GPS are mainly available in mapping devices, there's already a great proximity technology out there, deployed in literally hundreds of millions of cell phones: Bluetooth.
At Shoutpod we're taking the direct route to place: using Bluetooth and the mobile internet and hooking proximity networks into the global Internet. Shoutpod is bootstrapping proximity-aware interaction, rich precense, and place-history using widely deployed, existing technologies.