A slightly different method in InDesign is to use the GREP tab in the find/change box, it would probably depend on the source text on whether this produced the desired result compared to the suggestion from PricelineNegotiator.
GREP
Find what:
\r
Change to:
\s
( or perhaps ~. )
The above GREP may leave double word spaces, so then use the built-in GREP query to find/change Multiple Space to Single Space. I don’t know GREP/RegEx, so there my be a better method or a way to string the two searches together etc.
Stephen Marsh