Having a second photographer can help when you need photographs in two places at once, such as while the bride and her entourage are getting ready, but you would really like pictures of the groom, best man and groomsmen who are getting ready at the same time. Its also helps to have a second angle on important highlights of the wedding that go quickly such as the kiss and bouquet toss.
A second shooter helps the day go smoother by cutting down on the total time you spend on taking photo's on your big day. They help with lighting and managing the large groups of people wedding photography can entail, and they free up the primary photographer to concentrate on photography first, and leave the equipment hauling and other distracting details to an assistant.
My Husband Daniel has been accompanying me to weddings as a second shooter for over a year. He has also been with Daisy Digital since day one as tech and equipment support, website design and legal adviser.
You can see some of his wedding photos in the second shooter gallery.