Curious how long it takes to put together a memorial befitting an author of Norman Mailer’s stature? Oh, about five months. It was announced today that Joan Didion, Don DeLillo, Tina Brown, Sean Penn, William Kennedy, amongst others, will takes turns fondly recollecting the “id and (the imp) of American Literature” at the April 9 event at Carnegie Hall. Mr. Mailer passed away on Nov. 10 of last year. The memorial, hosted by Charlie Rose, is open to the public, but free tickets are required; they can be picked up only after 11 a.m. on the day of the memorial at Carnegie Hall.