Small, dense, sugary heart-shaped candies that usually come in pastel colors like violet, orange, green, and white. They have little phrases, almost always 2 words less than 5 letters in length, "typed" on them in a different color, always in CAPS.

These phrases include things like "LOVE YOU", "HOT ONE", "MARRY ME", "CUTIE PIE", and so on.
I imagine that conversation hearts were invented by NECCO, the New England Confectionary Company, because almost all of them taste like they were made from the same stuff NECCO Wafers are made of.

Last night I found a white conversation heart that said "MOON BEAM" in pink letters. I couldn't help it, I had to do something with a phrase so amusing, so I took out my black fabric CD case, and turned on my halogen desk lamp, and put the heart on the center of the case. Then, I took a digital photo of it, and edited it so that the black fabric looked like a long, black brick wall, and that the white conversation heart looked like a beam of light shining onto that wall. I think I'll make it my homenode pic when I make level 6.