Two sentences that have the same words but different meanings.

[tpk-nyc]

Using the same word in the same order I like:

Call me Ishmael.

vs.

Call me, Ishmael.

However, if this is not an issue of word order. For word order, you're looking at the subject/object relationship as in:

Man bites dog.

vs.

Dog bites man.

[tpk-nyc]

For an interesting play on subject/object, consider the sentences:

You know him better than I.

vs.

You know him better than me.

They mean completely different things. Fuller versions of the sentences would read:

You know him better than I know him.

and

You know him better than you know me.

This is not an example of word order but of "case," which is related to word order. Both are used to define the subject and object of a sentence.

Many people are sloppy when it comes to sentences like these. They use "You know him better than me" to mean "You know him better than I know him." This is not merely incorrect (in a fussy grammatical way) but confusing.

[Tantalust]

"Hey, it was the least I could do!"

[Francois]

Moving the position of "only" in a sentence can have drastic (and humorous) changes:

"He told his mistress that he loved her."

Put "only" in various places to get:

Only he told his mistress that he loved her. (Nobody else did)
He only told his mistress that he loved her. (He didn't show her)
He told only his mistress that he loved her. (Kept it a secret from everyone else)
He told his only mistress that he loved her. (Stresses that he had only ONE!)
He told his mistress only that he loved her. (Didn't tell her anything else)
He told his mistress that only he loved her. ("I'm all you got, sweetie--nobody else wants you.")
He told his mistress that he only loved her. (Not that he wanted to marry her.)
He told his mistress that he loved only her. (Yeah, don't they all...).
He told his mistress that he loved her only. (Similar to above one).

[wannabee]

Garage Sale

(however do you get it home?)

[poletop1]

Let's eat, Jack.
Let's eat Jack!

[Zea mays]

The classic:

A panda walks into a café. He orders a sandwich, eats it, then draws a gun and proceeds to fire it at the other patrons.
“Why?” asks the confused, surviving waiter amidst the carnage, as the panda makes towards the exit. The panda produces a badly punctuated wildlife manual and tosses it over his shoulder.
“Well, I'm a panda,” he says, at the door. “Here, look it up.”
The waiter turns to the relevant entry in the manual and, sure enough, finds an explanation. “Panda. Large black-and-white bear-like mammal, native to China. Eats, shoots and leaves.”

[cpaterso]

Originally Posted by socrates

I need an example of sentences that use the same words in different orders to mean different things.

I work hard when I am having fun. I am having fun when I work hard.