I was at a mates wedding at the weekend. The photographer was a mate of mine. Throughout the ceremony (which was in a catholic church). He went where-ever he saw fit to get as many good shots of the ceremony as possible, including behind the alter during the proceedings.
As I have photographed one wedding myself, and although I tried not to annoy people with flash during the mass, I thought this was fairly OK behaviour. However talking to people afterwards I noted how some found it somewhere between funny and annoying how he did this.

Which made me wonder....
What is acceptable for a photographer to do during a wedding ceremony, (including use of equipment, flash, positioning, moving around, getting in the way of people and all that) and secondly what would mean more to a couple; having loads of great shots of their big day or being pissed off by a photographer potentially buzzing about during their would be perfect wedding ceremony?
Thoughts?