Your tribute to the happy couple becomes something else entirely when it gets whispered (and garbled) around the table.
An instruction card placed on a guest's plate prompts him to initiate a toast, which will travel from ear to ear until it makes it back to him. He then announces his original toast, as well as the table's mangled version of it.
Download the PDF and print onto paper. Cut in half using a paper trimmer or a craft knife and metal straightedge. Place one card on each table; the guest who receives the card should start the game.