dirtydog said:Something else you see on these forums and lots of other places are things like:
"on it's own"
which makes as much sense as writing their's, your's or her's.
Most people seem to think it is correct though, but they are of course wrong.
They are not far from the correct usage though, so it's not exactly a million miles away.
It's can be used to abbreviate it is. (It's cold in here.)

) do not require apostrophes as they are technically words in their own right, so C'P'U's wouldn't make sense. As such, CPUs is perfectly correct as a word
Although it's pretty much been accepted in the English language, it's something I've always considered grammatically incorrect, as its meaning is ambiguous, not only in pronunciation, but also in writing.