nesting datagrid to unknown level

Hi

I have requirment to nest the datagrid. nesting of datagrid is easy. and we can find many articles on it.
But here problem is nesting of datagrid is on runtime, and to unlimited levels.
Like main category has sub-categories, these sub-categories can have further sub-categories, nesting level is not known......

please provide any resource/sample code/article to do it. We can use Datalist control. But we don't want to use TreeView control as we want to show 3/4 fields at a time.

Thanks and Regards,
Azam.