Well, thanks to Google, I now know what the T in a countdown stands for. Of course, I 'm not going to tell you what it means....should I make you guess???
You really wanna know, huh?? It's pretty simple actually. The T stands for Time until launch. Told you it was pretty simple! Although, not I am tempted to use it as a countdown for lunch as in : Time until lunch...hee hee, I am very silly today!

it stands for "time"

http://answers.yahoo.com/question/index?qid=20071105195530AAPvoIa

lol ok well i red this and then i sed in my head well sis im going to find out for you so i googled it and fond a good one so i hit copy and then right befor i clicked back over to yr blog i sed i bet someong told her alredy seeing how this is from like july but any ways i sall you had 2 comments and sed yep thats what it is someone told her alredy and shr enuf i was right but here is what i found any way te he Time of flight.....

since the flight hasn't begun yet it is Time Minus 10, 9,8,7,6,5,4,3,2,1, liftoff

T plus 1,2,3,4,etc...........