I've seen claims this is an ancient tradition of Chinese origin, but I cannot verify if that is true. Regardless, it is exceptionally sweet and is a fantastic visible metaphor for demonstrating the couple have a dedication to remaining joined together for the rest of their days.
There are several ways the ritual can be done. The couple can use a pair of heart locks that they padlock together on a single chain, or as shown in the picture to the left, the couple can use a single lock and secure it to a permanent structure.
I tend to favor the heart locks on a chain as the couple can keep that as a memento of their wedding day and do not have to worry about the lock being broken and removed at some subsequent date. I can only imagine what Brevard County would do if a chain link fence at one of the beach parks became filled with love locks.
The lock and keys can be purchased on-line and personalized with names and dates, or a plain old padlock from Home Depot would suffice. Though probably not as attractive by any means.
I thought I might take a stab at writing the wording for a Love Heart Lock Ceremony just in case I can entice a couple to include it sooner or later.
(Names) have just pledged their lives to one another, symbolized with the giving and receiving of rings. They wish to further symbolize the strength of their commitment with a Love Heart Lock Ceremony.
These two padlocks represent their recognition of the dedication and courage necessary for securing a strong and healthy marriage. I invite them to now attach their locks to the chain which is in the form of a circle, symbolic of unity, wholeness, and completion. (Names) have united in love and trust for a common purpose, for what was separate will now become whole and complete.
(Names), please take the keys and secure your locks. As their hearts, bodies, and minds are joined together in a bond that constitutes the sanctity of marriage, these locks demonstrate that (Names) are forever joined together in a lifelong partnership and an abiding friendship, a promise between two people that they will forever strive to both complement and complete one another.
At this time I ask (Names) to dispose of the keys, for what their love has brought together, let nothing break asunder.