There have been ongoing news reports about the nuclear power plant problems in Japan following the earth-quake and tidal-wave. The Wikipedia page about the Fukushima I nuclear accidents seems to have the best current summary of the situation [1].
I think it’s worth noting that Potassium Iodide can be ingested to reduce the incidence of thyroid damage in the event of radiation leaks (which apparently usually contain radioactive iodine). KI can be ingested immediately after exposure and there’s apparently little harm in taking it before a time of risk (it can be good to take it for a couple of days before exposure). So getting some KI right now might be a good idea for people who live in the vicinity. Apparently the Japanese government have issued iodine tablets to the people closest to the disaster, but it’s probably worth spreading the word to people who are further away.
The Nuclear War Survival Skills site has a good description of how to make your own KI solution [3]. This probably isn’t a viable option for anyone in Japan unless they can raid a chemistry lab as mail-order of chemicals will surely be too slow. This is probably something that’s best considered for future plans for anyone who lives near a nuclear reactor.
It would be good if airport pharmacies sold packs of KI tablets for the benefit of travelers who don’t live near a reactor but who are visiting a country that has them. It’s something I’d like to buy before my next trip to Japan.