Lemme try to explain this clearly.
We're working on a project for the Architecture Department in the local university. The project is to track the path/space occupied by a person inside a certain room. The idea is to fix the camera in one place, and shoot the person moving around the room.
The final result wanted is a video of the room, and you can see a man walking around, leaving a trail behind him (copies of his image). Kinda like a strobe/ghost effect, but the image of the man stays there for a while.

Can this be done in video? or is it much easier to take snap shots (using a digital camera) of the man moving, and blending the pictures in Photoshop?

Equipment: Canon XL1s + Adobe Premiere or FCP HD

If I understand you correctly you have multiple tracks with the
same footage slightly offset in time from eachother. Then blend
these together with varying degrees of opacity (tranparency)
and you will create the lagging look etc.

try doing in post using premiere filter, echo.

ed

Another option would be to export still image files of frames at a particular interval, then add each image to an overlay track with a degree of transparency as each frame is reached in the video clip.

You should result in having a smooth video the the person walking (which you wouldn't have with a still camera source) that leaves a trail of transparent still images where they walked.