I've always liked.....
Time flies like an arrow, fruit flies like a banana.
There is even a wiki page for it http://en.wikipedia.org/wiki/Time_flies_like_an_arrow;_fruit_flies_like_a_banana
and gives 9 different way to interpret it....
(as an imperative) measure the speed of flying insects like you would measure that of an arrow - i.e. (You should) time flies as you would (time) an arrow
(imperative) measure the speed of flying insects like an arrow would - i.e. (You should) time flies by the same method that an arrow would (time them)
(imperative) very quickly measure the speed of flying insects - i.e. (You should) time flies as quickly as an arrow would (be or move)
(imperative) measure the speed of flying insects that are like arrows - i.e. (You should) time (those) flies (that are) like an arrow
(declarative, i.e. neutrally stating a proposition) all of a type of flying insect, "time-flies," collectively enjoy a single arrow (compare Fruit flies like a banana)
(declarative) each of a type of flying insect, "time-flies," individually enjoys a different arrow (similar comparison applies)
(declarative) each of a type of flying insect, "time-flies," individually enjoys an occasional arrow when there is an opportunity (compare: "He prefers beer, but I like a martini")
(declarative) the common metaphor "time," moves in a way an arrow would (which, depending on the context of the phrase may mean "moves in a straight line", "moves by parabola", "its movement depends on the wind", etc.)
(declarative) a copy of the magazine Time, when thrown, moves in a similar manner to that of an arrow.
Language is such fun ;O)
bob
