although this quote is speaking of lust and not love. . . .

"Lust is the ape that gibbers in our loins. Tame him as we will by day, he rages all the wilder in our dreams by night. Just when we think we're safe from him, he raises up his ugly head and smirks, and there's no river in the world flows cold and strong enough to strike him down. Almighty God, why dost thou deck men with such a loathsome toy?" -Frederick Buechner

Yes, I remembered the "gibbers in our loins" quote. I just did not remember who said it. It is rather saying the same thing more evocatively than my friend's way. It isn't bad shorthand, though.

Does the Bible call all men to singleness? How does this relate to "be fruitful and multiply?"

Unknown, no, I do not think God calls all men and women to singleness. He does not even call most to singleness. In fact, because of the creational mandate that you mention, I believe the "nomal setting," so to speak, is for humans to get married. And, though I am somewhat more tentative on this one, the normal setting for most families should be to have or to acquire children i.e. through adoption.

There is an interesting passage in I Corinthinians 7 in which Paul says things like, "It is good for a man not to marry. But since there is so much immorality, each man should have his own wife, and each woman her own husband." He goes on to encourage the unmarried to stay so, but he says this principally, I have been told, because he believes "the time is short" before Christ returns and the judgement, though the passage does not directly indicate this latter point.

Paul says singleness is a far more pragmatic option if one is involved in full-time ministry as one's attention is not divided between ministry and a family. This point is practically absolutely true. Of course, Paul was not against married clergy or marriage as an institution, though.

So, then singleness is a gift (yeah the one that few, at least intitially, want) that is given to some people. How do we know we have this gift? Perhaps our circumstances i.e. what sort of work we are good at and the question of whether a wife/husband fit in well with this work is salient. Also, am I ultimately able to not burn with passion and desire (Paul says in an oft and perhaps ill applied passage, that it is better to marry than to burn with passion). And, finally, does it become evident to me that singleness is the desire of my heart. That last one is a tough one to imagine, but there are faithful single folk and God says the if we trust in him he will give us the desires of our heart, so it must be that that is either a desire of some folk or that God births that desire in them.