Some useful links to the radiation levels in Japan, especially Tokyo and Kanagawa.
Radiation in Japan (all prefectures): Air
Radiation in Japan (all prefectures): Water
Radiation in Japan (all prefectures): Rain
Radiation Overview, Yokosuka Military Base: Air and Water, 6h - 24h - 72h
Geiger Counter - Hino, Tokyo
Radiation Overview - All Prefectures of Japan: Collected data from different resources
Radiation in Water: City of Kawasaki
Microsievert: Display of Radiation
Radiation Early Warning System: Radiation in Austria (for comparing with Japan)
Other useful links:
Earthquakes in Japan: Yahoo Japan
Weathernews: Weather and wind direction, Tokyo
Will be updated, if I find other useful and interesting links. fujimi-tea