Android :: Memory Management Outside Heap

I am working on an application for android and we since we have lots of graphics, we use a lot of memory.

I monitor the memory heap size and its about 3-4 Mb , and peeks of 5Mb when I do something that requires more memory (and then goes back to 3). This is not a big deal, but some other stuff is handled outside the heap memory, like loading of drawables.

For example if I run the ddms tool outside eclipse, and go to sysinfo, I see that my app is taking 20Mb on the Droid and 12 on the G1, but heap size are the same in both, because data is the same but images are different.

So the questions are: How do I know what is taking the memory outside the heap memory? What other stuff takes memory outside the heap memory? Complex layouts (big tree) ? Animations?