Before all the mashups and nouveau mapping, a tiny company called Metrobot, run by Geoff Campbell, was doing some very different things with maps. The tool provided something like a graphical version of what A9 has done with its block view. One could take a virtual stroll around a neighborhood and see where businesses were situated in relation to one another on the street.
I believe that Metrobot had some meetings with the folks at Google and Yahoo!, which later developed their own different and very feature-rich mapping tools. I hadn't heard from Metrobot in a long time, and suddenly the company resurfaced last week with a press release.
Metrobot has now done a relaunch of sorts with expanded coverage, Google maps (as an adjunct to Metrobot's own maps) and contextual advertising. It's still quite different from other things out there and worth a look. The wireless arena, in fact, might be the best application of this approach to mapping.