I’ve been hearing about “virtual graffiti” systems for a while, but now there’s some stuff actually happening. The idea is to be able to place virtual notes in spaces that would be accessable through cell phones and the like.
Geonotes (via Many to Many) from Sweden have a wifi based solution, but it only works with Lucent base stations. Still, from my understanding of it, anyone with Win2k, Linux or Savaje OS, a wifi card, and the GeoNotes could leave a location specific note in a Lucent base station (even if the base station doesn’t have special software installed?).
An experimental system in Helsinki called Flirt enabled mobile users to leaves virtual messages or ?hanging data? in specific locations which would be picked up by the next user to pass the same location. The experiment turned the city into a chatroom of flirty Finns.
And here are some fun things you could do with some of this tech: Location Aware Game Ideas
(via Head Map).