I've heard (meaning that i have never tried to do it) that getting a UV filter (obviously one which is the right size for the lens you wish to use) and gluing it to a suitably sized opening in a large zip-lock bag is a good way of doing things - you wont get the filter back unless you use pvc glue or something - but then it wont hold very well anyway...
Or - if you have a screw mount lens hood, no glue is needed, just screw it on over the hole trapping the plastic in the thread and carfully cut off any overlap - tho i think with this method a polythene bag might be a better idea considering the thickness of the plastic and the possibility of ruining the thread in the screw.
I realise that the weekend is over and that was when the wedding was, but just thought i might add another option for people to consider. when do we get to see pics? or better still - pics of you underneath a pink brolly with your cam ;)

"In every colour, there's the light.
In every stone sleeps a crystal.
Remember the Shaman, when he used to say:
Man is the dream of the Dolphin"

Rich Meadows Photography