Robot controlled from anywhere in the world

I am working on a robot which can be controlled from anywhere in the world. I am planning to use arduino mega, ethernet shield and wireless router installed on the robot. It will send the live video feed to the internet somehow and it will receive instructions from internet as well from a person sitting in another city or country. I want to use the easiest possible method to achieve this. Is arduino ethernet shield is the correct tool to achieve this task. Or is there some other some other suitable device? Please help me in this.

It think it can be done.
You can buy an "ip cam" for the live video.
What will the controller be ? a computer or also an Arduino ?