I think what I want to achieve is a way to assign a grouped product to more than one parent, but that is not allowed.
A simple example would be having a camera body and at time of purchase adding a lense from a list of lenses (I envision the grouped product table whereby a person adds a lense or maybe 2 lenses). This issue is that once you assign that lense as a grouped item and select the body as the parent - you now are not able to assign it to any other camera body that the lense would be compatible with. Does this make sense. How would you approach this? I like the fact that the grouped products add links to grouped product details page and it is easy to add the item for the visitor.
The only other solution I can see might be with variable products, I think.
The example above is an illustration of my application - what my client is really selling are Satellite phones and with the phone he wants to give visitors the ability to add a pre-paid card of minutes. There are various minute packages and of course these packages are available to more than one phone.
Thanks for your help and suggestions.