How may CF cards do you use at a wedding/event?

[jaayres20]

So I have been shooting weddings for about 3 years now and I have never had a card issue yet but I know it will happen one day.  I only use extreem pro SD or Lexar Professional cards.  I have herd over and over to use small cards and that way if one fails you haven't lost everything.  My thoughts on that is that if a card is in a camera it is also less likely that it will get lost or stolen than 3-5 cards in your bag/wallet.  One time I ejected one of my CF cards a little too hard and it flew out on the ground.  So I don't really like removing cards unless I have to.  So I guess there are pros an cons to both ways.  Since the 5D3 came out I have been putting two large cards (64GB) in the camera and just leaving them in there the whole 12 hour day.  If the camera is backing up to both cards I should be okay for the most part.  I just herd today of a case where a camera produced some kind of charge that killed both cards so now I am nervous again.  Has anyone ever had both cards in there camera fail before and how likely is that to happen?  I will be happy when the technology is good enough that you can instantly transfer your images to your laptop quickly and wirelessly.  I know the technology exists now but I don't think it is fast enough to transfer large volumes of images quickly.     

[Mt Spokane Photography]

I think its smart to be paranoid about losing images, but I haven't heard of a camera zapping both cards.  How many images have you lost in the past?
 
The technology is here NOW to quickly backup your images to a remote device, Canon has a wifi transmitter that is high speed, or you can get a slower EYEFI card to backup up your jpegs.  It can back them up as you go, and why worry if it is not instant, if it gets behind, it will catchup when you take a break.
 
For really important big money projects, multiple backups are made ASAP and kept in different pllaces so a single event like a fire, plane crash, etc will not get them all.  Even then, money is not unlimited.