No experience? No problem.
Retired Justice O'Connor told Good Morning America that Elena Kagan's lack of judicial experience is "fine. Just fine," and that the Solicitor General seems "very well qualified academically."
Justice Scalia agrees. He told a group at Catholic University, "I am happy to see that this latest nominee is not a federal judge -- and not a judge at all."
On the other hand, it's okay to continue your judicial experience after retiring from the Supreme Court. Justice O'Connor frequently hears appeals on the 9th Circuit. And this article describes retired Justice Souter's service on the 1st Circuit.
(h/t How Appealing)