While travelling, especially overseas Skype is very useful to keep in touch. At times, I pay for SkypeOut to make International phone calls and find their conferencing feature exceed expectations. The only requirement is for you to have a good broadband connection.
Anyways, for you to use Skype you need to carry apart from your laptop and mouse, additionally a headset. Recently while in Tokyo I bought this convenient device from Sony that combines a mouse and a Skype Phone (USB) for about Yen7500.