Recently we received this as a favor at a wedding we were in:
It's a love block. You take one home, and you and your spouse take turns hiding it for each other in places you know it will be found unexpectedly. It serves as a little love note, a reminder that your spouse is thinking of you even if he's not there.
Sometimes it's a few days before we find it, and other times it's hidden several times in one day.
It is by far the best wedding favor I have ever seen.
It's fun to come up with a new place to hide it.
It's been in sock drawers,
In medicine cabinets,
And it always makes you smile when you come across it :)