I would love to see it in modrana and have commented in that thread, but something plugged in to Telepathy(or a FOSS replacement) would probably ease the plugin and make it easier to run in "location beacon" mode via icecondor so people can see you even if you aren't running a app to scan and map for them, maybe a daemon that will alert when someone enters a set proximity as in the video above.
I really wish that it could also plug into Sygic but this seems nearly impossible.