I just came across Henry Seltzer's great site/blog, The Press Gaggle containing various interesting (and often funny) quips and quotations from the White House Press Briefing Room. It's well worth it to take a little time to read through some of the previous entries. I particularly like this one (April 11, 2002):
MR. FLEISCHER: Good morning. Let me give you a --
Q. Good afternoon.
MR. FLEISCHER: Within one minute of my briefing I already stand corrected by Helen [Helen Thomas I presume, a very longstanding member of the White House Press Corps]. Good afternoon. Let me give you a report on the President's day and take your questions.