If you have After Effects, one of the most popular current effects is to add a pseudo third dimension to a photo. Here's the general idea:
1. Cut out the person or other foreground object(s) and place in a separate layer.
2. Fill in the background that used to be obscured by the foreground object, using clone and other tools.
3. Apply a 3D effect to the two layers.
4. Move the point of view. Watch the foreground object move in relation to the background (parallax).
A detailed tutorial on this effect was published in last month's EventDV magazine by, if I recall, Jan Ozer.