The quote
The only reason for time is so that everything doesn't happen at once.
is attributed to Einstein with some regularity. (For example, Google returns 47,700 results, of which all except 5,780 include the word Einstein. Google Books returns 645 results, of which 14 don't include the word Einstein.)
However, on Albert Einstein's Wikiquote page, which is pretty thorough from what I can see, there is no mention of this quote.
Did he really say this?