The word "poetry" is itself a dactyl, as pointed out in the New York Times Crossword Puzzle (Will Shortz, ed.) for May 31, 2006. A useful mnemonic for remembering this long-short-short pattern is to consider the relative lengths of the three bones of a human finger: beginning at the knuckle, it is one long bone followed by two shorter ones.
An example of dactylic meter is the first line of Henry Wadsworth Longfellow's poem Evangeline, which is in dactylic hexameter:
The first five feet of the line are dactyls; the sixth a trochee.
A modern example is the Beatles song "Lucy in the Sky with Diamonds":
Written in dactylic tetrameter, the verses of the song have the rhythm of a waltz. The word "skies" takes up a full three beats. Dactyls are the metrical foot of Greek elegiac poetry, which followed a line of dactylic hexameter with dactylic pentameter.