Paul Goldberger of the New Yorker, in conversation with Kurt Andersen, calls for a broadcast tower on the Twin Towers site, one as ambitious as the Eiffel tower was in its day. Listen to the interview; here's an excerpt:

What we really need for that site is the Eiffel tower of 21st century. Something that would use the technology of our time with the brilliance that Eiffel used the technology of the 19th century to create beautiful object like that. And considering how much we do in New York need a new broadcast tower. To not do it at Ground Zero, and not use it as occasion for a very tall tower is a little crazy.
[Studio 360 via Jarvis]