How to record a video with multiple perspectives like the yogscast?

I really don't know how to explain this but. When they record example: first lewis plays a bit than simon says he found smth and than the camera perspective changes to him. Than when Duncan finds something the perspective changes to him and how he sees and plays minecraft, so they keep changing their perspectives. So can this be done the hard way by cutting and combining their videos into one so at certain moments their perspective changes or there's another way to do it. I have sony vegas pro 11 and fraps so how do i do that.

Added (1). Wow really helpful Kieran… If thats the case mind showing me a tutorial video about it if it's not too much to ask

Editing.

As much as uninformative Kieran's post is, he still hit a bullseye. It's simply all editing, and not very advanced one either.

Both players are playing the game and at the same time recording their own perspectives. When they are done they bring the recorded footage to their editor(possibly one of the players). The editor starts putting up a video together, lets say in Sony Vegas. He puts in the Player 1 recorded video into the Sony Vegas project, then at some point stops the video, cuts it and places a Player 2 recorded video and fast forwards to the point where the previous video has been cut off. Then the same way he switches back to Player 1 video.

It's very basic stuff but might take some time reviewing the footage and making very smooth transition so people won't even notice that a video had been just cut. Though it's expensive to have two gaming computers and both being able to record the game smoothly. If Player 1 and Player 2 won't record at the same game resolution and same graphics options then it will be noticeable when who's perspective is playing right now, not really a big issue though even people would notice it. Yogscast are not poor and they can afford any and as many PCs as they wish for their videos.