I read this post and decided to see if I could recreate the effect. I agree with Glenn that you need to make a large photoshop file of the background to start off with. My experiment was done entirely in Vegas 5. No cameras were involved. It's actually quite a simple effect. Hope the link works, sorry the video size is so small.
http://mysite.verizon.net/res7b5yh/sitebuildercontent/sitebuilderfiles/vega...
Here's how I did it:
In Photoshop, I created a 1920x1080 image of the background with all the pictures in it. I also made 2 white boxes where the video will go. I imported that image into Vegas and made it 1:30 in length. My project size is set a 1920x1080. I placed a video clip on a 2nd layer and used crop/zoom to 'shrink' it down over one of the white boxes but leaving some white border showing. I repeated this with a 2nd clip on a 3rd layer. I rendered this out uncompressed to keep the 1920x1080 resolution. Close this project.
I opened a 'new' project with a canvas size of 720x480, imported the uncompressed video clip into this project and used crop/zoom to Zoom in and appled keyframes to make the pan moves from one photo to another. Render this out at DV resolution or whatever you like and you've got yourself an effect! Hope this helps!
Harlan