I played a wedding last year. The woman (who seemed to be in charge of everything) made an interesting annoucement prior to my beginning. I had a guest mic set up. She asked that if people wanted the bride and groom to kiss, all they had to do was wait 'til the end of a song, by the guest mic, and tell some sort of amusing anecdote about the bride and groom, to get them to kiss. Everyone seemed to enjoy this and to be honest, my playing time was almost cut by a third.
Just thot I'd mention this interesting way of approaching an age old tradition.