Letting the camera move along different paths What I want:

I have a model of a room with several objects in it. I want to see the objects in the room from several camera positions on three of the four walls. Basically, I want to let my camera follow predefined paths along these walls.

What I did:

I could not figure out how to make a path looking like an open rectangle, so I decided to create three different paths, one for each of the three walls. I managed to let my camera follow one of the paths nicely. However, I do not manage to let my camera jump to the next path/wall once its done with the previous one. According to this thread http://blenderartists.org/forum/showthread.php?204414-Follow-one-path-after-another-in-Blender-2-5 it should work with object constraints and the influence value, but since the blender file given there is not available anymore, I can't figure out how to do it. So, how would you animate the camera for this purpose?
No need to use multiple curves:


Add a circle (ShiftA> Curve > Circle)
Switch to edit mode (Tab) and set the handles to vector (V> Vector)
Delete one segment by selecting two of the control vertices on one side and pressing Delete> Segments.




To align the curve to the axes, rotate it 45&deg; on the Z (RZ 45).