@margo,
I can't believe it myself, but I actually participated in a Lara Bingle discussion the other day!
It was about the ring ethics.
Now, I consider engagement rings to be utterly ridiculous...but, it seems to me that if the engagement is called off and you have been stupid enough to have the damn thing, the woman is ethically obliged to give it back to the fella (or whatever the gender is of the person who gave it).
Apparently legally this is not so..it is a gift.
I was shouted down. The general feeling seemed to be that he must be a rat if the engagement was broken off, and he deserved to lose some money.
I think that is an appalling approach.
However you look at it, flushing it down the loo seems rather futile. Sell the stinking thing and give the money to charity if you must make le grand gesture! But I think the fella deserves as much of his money back as possible.