While Quarterscope pursues worldwide wardriving to build its virtual GPS database, the open-source Herecast project expects more grassroots contributions: A few weeks ago, we wrote about Quarterscope, a company which combines a database of wardriving-based GPS and Wi-Fi access point data with live information from a Wi-Fi card to produce a virtual GPS. Mark Paciga wrote in to point to his nascent effort, Herecast, which is an open-source project to develop a similar resource that's a little more open-ended as to goals. It can combine mapping, location information (you are here/you are near...), and friend finding.
The system doesn't use GPS mapping either on the input side or output side, but rather tries to use wayfinding through naming of familiar places in the vicinity. Paciga notes that it only took a few hours to mock up functional demos. It's available now as a Pocket PC beta, but he hopes to port it to Windows XP as well.