Hi there, I'm Naree!
I use Force Fins. http://www.forcefin.com/
They are REALLY great for vibram wearers - they, much like our weird new shoes for humans, mimic the natural movement of fish fins. Plus, you can fit your vibrams in them. Or you can go barefoot in them - they come with a neat little insert so the fins fit snugly against the top of your feet.
They are designed so well that you can swim significantly faster in them, and - when you scuba dive - you end up using a lot less air (it takes less energy to propel yourself forward). They are also significantly shorter and lighter than regular scuba fins, so they are easy to pack in a carry-on. I LOVE my fins!
One tip - you should try them on in a store. Much like Vibrams, the sizes can surprise you. And much liek vibrams, you'll find that you swim differently with them than with conventional fins - less kicking from your hips, and more subtle action from your ankles and calves.