An emote on some LPMuds indicating raising one eyebrow ala Spock. Vaguely has the meaning "Is that so?" Used in online chat context to indicate disbelief or surprise.
Doug: beat your kill streak record in COD4 the other day
Trent: *spock*
Doug: no really, it was like 7 right?
Trent: try 17
Doug: ...well, I got close... heh