My sister-in-law sent this awhile back as a video, but it's good in just plain form:

What nine-letter word in the English language continues to remain a word when each of the nine letters is removed one by one?

The word is

STARTLING
STARTLING = STARTING
STARTING = STARING
STARING = STRING
STRING = STING
STING = SING
SING = SIN
SIN = IN
IN = I