The guys over at XKCD created this wonderful chart detailing the amount of radiation you get from just living your daily life and how it compares with the radiation dosages in scary disasters. It's comprehensive, informative and serves as a great reference point given Japan's current situation.
More from Gizmodo
Trent Reznor and Atticus Ross Win an Emmy for Watchmen, Coming One Step Closer to the Broodiest EGOT Ever
What's the main source of radiation in an airplane?