Via Libby Miller, Balog : Location-based information aggregation system (.pdf) by Hiroki Uematsu, Kosuke Numa, Tetsuro Tokunaga, Ikki Ohmukai, Hideaki Takeda. Their representation of location data in RSS is interesting in this regard

Balog is a location-based information aggregation system with GPS-enabled mobile phones. Balog system collects location-based information via E-mail and RSS and represents it either with association with maps or with the weblog style, i.e., entries near the location displayed in reverse chronological order. We also propose representation of metadata for location embedded in RSS and its utilization.