Crowdsourced data, commercial, and DIY radiation detection and mapping

Crowd-sourced post Fukushima radiation tracking is doing what it can to fill the public’s need to know. Readily available geiger counters range from $1095 to $50 with smartphone modules at the lower end of the price scale. Safecast, RadiationWatch, and GeigerCounters.com
Safecast is a global project working to empower people with data, primarily by mapping radiation levels and building a sensor network, enabling people to both contribute and freely use the data collected. After the 3/11 earthquake and resulting nuclear situation at Fukushima Diachi it became clear that people wanted more data than what was available. Through joint efforts with partners such as International Medcom, Keio University, The John S. and James L. Knight Foundation and GlobalGiving, Safecast has been building a radiation sensor network comprised of static and mobile sensors actively being deployed around Japan – both near the exclusion zone and elsewhere in the country.

Safecast supports the idea that more data – freely available data – is better. Our goal is not to single out any individual source of data as untrustworthy, but rather to contribute to the existing measurement data and make it more robust. Multiple sources of data are always better and more accurate when aggregated.”

GeigerCounters.com is about as eponymous a name as a web store can have:
GeigerCounters.com
Radiation-Watch is another DIY organization which has developed smartphone and Arduino modules.
Radiation Watch, Japan

Radiation and weather app

Radiation Watch, UK

Crowdsourcing Radiation Data