No arguments about the practical suggestions with regard to H2s, minidiscs etc. for weddings. You can't typically adjust a mic mid-ceremony so monitoring is less vital and you may be using too many mics to monitor them all closely anyway.

But in a professional setting if you are recording the primary audio you need to be able to ride the gain, and monitor the sound with headphones and meters. You notice a problem the second it comes up - you fix it, back to work.

Great advice. I think that I'll get a shotgun microphone for the camera and a Zoom H2 as a backup.

The venue will be providing a PA type system with about 8 microphones. I'll also run an XLR cable from their system to my macbook pro to make sure that I capture all audio.

Typically I've noticed that these unmanned systems can give feedback and other audio glitches that can ruin a recording.

Shotguns color the sound that comes in off-axis and in an acoustically live environment with a lot of extraneous sound the audio will suffer with a shotgun - think me64 as opposed to me66.