Quote Originally Posted by patrickv View Post
I remember once using two cards and a laptop, it worked pretty well (wasn't a wedding). Basically I had the laptop in a corner of the room, plugged into AC. When a card got practically full, I'd change the card for the empty one, continue shooting, and when I had a minute I could just slip the card in the laptop, and click on transfer. Once the second card was full, I had already finished the transfer from the first one a while ago so it was ready to use. 16G cards are fast to fill when I shoot action in raw format!!
Just ignore that silly post. A wedding only happens once. It's a bad idea. In that specific case, I did it as a "backup plan" because I had forgotten my memory card collection at home and I only had the two memory cards that were already in the cameras. I wouldn't recommend it if you can avoid it.

Myself (and other people) recommend to have enough memory cards to store everything and always keep them with you. Some wedding photographers even have a special pouch that goes under their clothes for memory cards. Gear can be replaced, a given wedding is something that happens once. An even better option is to have a camera that has two card slots, and as you fill these memory card pairs, put one in your own pocket, and give the other one to someone you trust to keep the backup.

Also, as a general rule, never format a memory card that contains anything important without having its data in at least two different physical locations. A nice option is cloud storage backup. There is some software that will sync your hard disk on some secure facility on the net, which is at a different place than your home.

Wish you all the best.