Farewell From The Crew of Alias (2:53) is an Easter egg. While on the bonus features menu, when "Bloopers Of Alias" is selected, press right on your DVD remote twice. The featurette is a montage of clips of the crew waving goodbye. There is no dialogue.

Taken from HERE - watch out for spoilers. :)

More Easter Eggs :)

SPOILERS again.

I don't know how many are on the S5 boxset, I've only found two so far: the one Sarah mentioned already and above that something on Balthazar Getty :wub: