so this is how it works if you have toast titanium and imovie:
when it comes time to export your imovie and you click on the export options list, you'll also have two additional choices from roxio, one of which relates to exporting for VCD (vidio CD). you select this option, click export, and it proceeds to do its thing. then when its done, toast ti opens and you're presented with its window and its ready to burn your VCD.
the VCD will not play in apple's DVD player app, so you'll need a consumer DVD player with VCD capability or a VCD player app for your mac.