See, I have been thinking about my own question, and I'm starting to think there is no such thing as unconditional love. This is simply because I can ALWAYS think of a senario that would cause me to stop loving someone. For example, if I had a boyfriend, and loved him, I would think that my love was unconditional... but then if he beat me, or cheated on me, or killed my mother, or something else like that, I'm pretty sure my love would stop immediately. Same with children. Obviously, I don't have any yet, but I DO have a little nephew (20 months!) who I have been babysitting all summer, from 7 am to 5pm every day. He is not my child, but I love him. Yet I cannot say that I love him unconditionally; as truthseekingsoul suggested, I would probably stop loving even him if he grew up into a "murderous paedophile" or a serial killer or something.
As far as I can tell, this means that love is conditional. Not unconditional. Certain conditions allow love to blossom (attraction, "chemistry", mutual interests, etc), certain conditions allow love to continue (kindness, faithfulness, communication), and if these conditions are taken away, love will die or simply will not develop...