Coincidentally, I've waited just long enough to see 9 correct answers -- so I'm proven right ("I bet at least eight of you will get it right away here"). I've now put the correct answer as a comment to my original riddle post.
Congrats to all 9! You are my math/logic Nazgul.
It was fun to see the stream of correct answers fall off logarithmically. boffo & candid each answered within ~5 minutes after my post(!). That was 22% of them right there! The next couple hours brought radium, other & spoonless. Then, yoak & simonfunk rounded out the first day & evening. pjammer stole a moment away from traveling to jump online as the sole successful contestant on the second day. Finally, the lone browascension dropped by an hour or two ago here on the third day.
(Moral: That's so yesterday sums up how we do things here in livejournal land!)