What has only been done as of 2006 by two adult stars Harpo Marx and Sean Connery at Chinese Theater?

This is a trick question!

* Harpo Marx died in 1964, so he could not have done anything at the Chinese Theatre in 2006.

* Sean Connery is alive, but he did not leave his hand and footprints at the Chinese Theatre in 2006.

The Chinese Theatre is known for its hand and footprint impressions of famous stars, but you're being misled about the year and the people involved.