Power outlet in Japan (overseas)

I have Ti/Al Powerbook purchased in NY, USA. It has the regular two-unequal-prong power outlet. Can I use my PBs in Japan. I know Japan and USA are similar in frequency (50hz/60hz) and voltage (100 for Japan and 120 V for USA). Almost all of Japanese electricnics are tuned for 50hz/60hz and 100 to 120 V. But, I am not sure about the shape of the power outlet. I heard some countries use equal prong outlet while some use unequal prong like USA. I should not be asking this question as I am originally from Japan (but I've been in states more than 10 years and my memory about it has been very hazy (or almost wiped out) at best.

Thanks for your reply. But, is it necessary to buy one as Japan and USA seem to have the identical outlet shape and voltage? I think most of US goods are compatible for either 50 or 60 hz. If someone who does frequent travel between Japan and USA is reading this thread, please chime in. I have the household-full of computers/electronics bought in USA which I may want to bring home in the near future.