(from Greg Black's signature as posted to bsdi-users mailing list)
 ech`echo xiun | tr nu oc | sed 'sx\([sx]\)\([xoi]\)xo un\2\1 is xg'`ol

(from Gerd Knorr's signature as posted to video4linux-list)

Get back there in front of the computer NOW. Christmas can wait.
        -- Linus "the Grinch" Torvalds,  24 Dec 2000 on linux-kernel

(from martin's signature as posted to the XFree86 Xpert mailing list)

[greetings from the heart of the sun]# echo madduck@!#:1:s@\@@@.net
(from Xavier's sig posted to linux-isp)
echo '16i[q]sa[ln0=aln100%Pln100/snlbx]sb20293A2058554E494Csnlbxq'|dc

One Unix to rule them all, One Resolver to find them, 
One IP to bring them all and in the zone bind them. 
attributed to Jesper Skriver, maybe starting in 1997.