Skype

This is a awesome service which allows me to call you people in the U.S. for only 2 cents a minute! (But you can go on feeling like you are important if you get a call from me - just because it's only costing me 2 cents, doesn't mean you aren't special.)
How it works: Basically, you download the program "Skype"(free) and this allows you to call other skype users(anywhere in the world), from your computer to their computer, for free. Next, you can download "SkypeOut" which allows you to call any phone number (in the world), including regular phone numbers and cell phones, very cheap. The per minute prices are listed on the website- calls from Japan to the U.S. are 2 cents, and to other countries the prices are almost the same. To use SkypeOut you have to have a PayPal or Moneybookers account.
The connection is not always great- especially if you are calling a cell phone, (and if you have a computer that rides the short bus), but for the most part it works OK, and the price is worth it! Skype also has Instant Messenger.