Calling the pharmacy and stopping by the pharmacy will not get you potassium iodide tablets. I do not know what you have heard on the news or read on the internet but potassium iodide will not save you from radiation poisoning. I repeat: Potassium Iodide Tablets Will NOT Save You From Radiation Poisoning!
Potassium iodide is only used to protect the thyroid gland. It does not protect anything else on or in you from radiation and its detrimental effects. In severe cases it will not even be enough to protect the thyroid gland so get over it.
The US government has stated that we (in the US) are in no danger from any radiation coming from Japan. However, there can be environmental consequences that would have widespread ramifications mainly involving sea life, shore life, and water supply contamination.
There is no point in getting yourself worked up over any potential nuclear meltdown. Let's not get all "Lord of the Flies" just yet. If it happens, it happens. We as a planet will deal with the consequences.