Make your laptop your phone
Skype—which lets you make voice and video calls from your computer
over the Internet—is great if you’re traveling with your laptop. You
can connect with other Skype users for free or call mobile and landline
phones for a small fee.
Pros: No service plan is required; software and computer-to-computer calls are free.
Cons: You have to be near your computer and it must be turned on; free calls are possible only with other Skype users.