Custom parts or other software to enable more granular permissions?

Does anyone know of a custom webpart or other product that would
provide administrators more granular control over permission levels in
WSS 3.0? Each specific permission option often contains multiple
functions, for example the List Permission for:

"Manage Lists - Create and delete lists, add or remove columns in a
list, and add or remove public views of a list."

I'd like to able to break this down and permit a user to add or remove
public views of a list but NOT create/delete lists or add/remove
columns.

I'd love to find something that gives me the ability to slice and dice
each component of the permissions as I need to.

Any ideas? Does such a tool exist?

Thanks