Here it is 2014, I'm using iOS 7 and I (and others I know) still have the same problem as the original poster of this thread. In my case I instruct fitness classes and, during the class, without any previous preparation, need to be able to scroll my library, select a song and have it play once. I am usually not at the iPod to prevent it starting the next song or repeating the same one. Sounds simple and logical but as far as I can tell, can't be done.
To repeat the original request... On my iPod/iPhone, how do I play just ONE SONG, ONE TIME? I have read the entire thread and I didn't see one person state the obvious...NO it can't be done and it is very frustrating.
It should be an option on the iTunes Repeat selection feature: Repeat all songs/Repeat this song/PLAY THIS SONG ONCE/No repeat (i.e. Play continuously from the library/list.
All those well-intentioned suggestions about making playlists, using special apps, using Dropbox, and even editing the original file in some way came via responders who (as was pointed out more than once) "didn't get it" or simply "didn't read the question".
Perhaps, though, in the intervening years Apple has actually included this ability in another area of the software. So I'll ask the question again: in my iPhone/iPod, how can, on the spur of the moment, I play ONE SONG, ONE TIME? If someone is authoritatively able to just say "Can't be done.", I thank you in advance. Nrpro