soft write barrier

I'm thinking about tracking changes to objects. I had a look at WriteBarrier on squeaksource. My goal would be to have something more soft that does not need to track class shape changes and most of the system notifications, just the state of an object. A second goal is to avoid having to use primitives but that shouldn't be too hard. The objects will be materialized via http and I want to have a good way to track those changes.

I can think of some approaches but wanted to ask for the clever ones :) What possibilities do you see to achieve this?

thanks,

Norbert