Over 150 Objects?

Unfortunately the project I'm working on really needs quite a few entities; 150 is kind of a drag and 200 would be more realistic. Of course my old Droid Incredible has a hard time pushing more than a 120 or so and I'm kind of using this as a minimum benchmark... As far as I know we still have no Billboard support built in but... I did a bit of searching but didn't find much.

I would love some kind of LOD that would switch over to billboards at a certain distance but I wouldn't be surprised to learn that calculating the distances of 200 objects alone would be a concern on mobile.

Any ideas?