I was curious to this, i see a lot around lately in a normal video shot then having text creep along something in the video, e.g: having a shot of someone standing next to a building and the text moves past the frame behind the person. In most circumstances i'm presuming no blue screen has been used so is this just nifty text animation or is there some easier way?

A good example is seeing it done on the Discovery Channel where they have a video of like a dog jumping and in post they've had him jumping over the text.

Any thoughts?