You need to do this:

Pull footage from both cameras, you will have two clips
Line em up one above the other (not sure if elements does this, but any "proper" video editing app will - look for "NLE" - Non Linear Editor - A linear one is only one timeline)

Now you need to sync them. You need either a visual or an audio cue for this (Flash of light, clap or something) that is in *both angles*

Slide the clips left and right until this cue is in the same place for both clips (as in above each over) HINT: in adobe, select a clip and ALT+arrows to slide a clip left or right by a frame. In older versions of premiere, you could right click a clip and "Add clip marker" to put a marker on the clip - put one on each angle where the sync cue is and visually line em up. Dunno how to do it in Premiere CS3 tho :(

They are now in synch - you can use the cut tool to cut sections out of the top angle so the bottom angle shows through. If you want to view the bottom one, to the left of the tracks in premiere is an eye icon. Click that to show or hide a track revealing the one underneath.

Once you have cut holes in the top one in all the places you want the bottom one to show up, you are done, render out!