samuel morse, sending his first message via telegraph:
"What hath God Wrought?"
Oppenheimer's claim upon seeing the mushroom cloud he helped sire:
"Now I am become Death, destroyer of worlds."
first message sent between networked computers during arpanet testing:
"LO" [meant to be "LOGIN" but a system crash put an end to THAT silliness.]
and now, me:
"*taptaptap* he-LOOO? *taptap* is this thing ON? anyone?"
...the devil's in the details...