Yes. Feasible. But what the others are talking about is the event of a card failure. If you have only 1 card, and it fails, you are screwed. Sometimes, you get read/write errors on the card, and you can attempt to recover the files on your PC before reformatting it. If you dun have a 2nd card, you cannot shoot anymore until you buy another card or you reformat your card, losing all your pics in the process. The chances of 2 cards failing is much smaller than 1 card failing.
Personally, I use 2 cards : 1 x 1GB and 1 X 512MB. These gives me enough capacity to shoot a whole day using RAW or highest quality JPG. And yet if one of them dies, I still have enough to last me quite a lot of shots.
Some people prefer using larger number of smaller cards. While this may be "safer" from the card-failure statistical point of view, it however greatly increases your chance of dropping a card while swapping and damaging it. So you have to find a compromise of number of cards and size of cards.