>I thought about doing that, but if the data is not saved, creating a new instance won't work. The problem is further complicated when moving to COM. How do I enusre that the current instance is used for the bizobjs?

You could scatter the data out to an object then pass this data down through to the child object that requires it. If you need data from more than one object for validation to occur, you can use a "parameter" object (see the Wiki for info on this). I created one that I use a LOT for my web applications. It automatically adds new properties on the fly when you set any values, and returns an empty string if the property doesn't exist. I pass this object around whenever I need to do validation.

In COM, if you're not using an event object, you'll create each object and manually set the child object references. You can use these references to pass the same data back for validation.