An update to the "dilema" I posted about

[BigVinnie]

A couple of suggestions. You did not state what the venue was so I am taking a stab in the dark.

Since you are taking a spare body you should setup a remote for it. You can use something cheap like an RF-602 remote or rent a set of pocket wizards. You will need a flash remote anyways.

During the ceremony find a high vantage point and lock down the spare camera. Especially if no flash is allowed. Set your pocket wizard in the hot shoe to fire the remote camera every time you take a mobile shot. This gives you a rigid mounted camera and a second perspective. I've had as many as 4 cameras setup this way during the ceremony. It is like have multiple shooters for free.

Take a look at this little goody from Kacey Enterprises. For shooting candid photos a pole, remote strobe and medium umbrella can really enhance the lighting. Even if you don't have an assistant you might be surprised how easy it is to recruit a bored adolescent to give you a hand.

Most of all don't stress.