Others may have known this before, but I just tried it and it works for some of the transitions/effects from previous versions... I use the water ripple effect in almost all of my projects (about a 5 second clip with a slo-mo added as well). Much to my dismay, this effect is not part of iMovie4. So I duplicated the "ripple.bundle" from a previous version of iMovie2 and dropped a copy into iMovie4 (Control/Right click) > Show Package Contents > Contents > Plugins Now I have my water ripple effect back. Cool ! P.S. I don't think you can take an iMovie4 .bundle and place it in the iMovie2 or iMovie3 Package. But why would you want to ? ;-)