I would not recommend using the 1.1 setting. Even at 4 x 6 sizes, you will probably have lots of graininess.
I always leave mine at the highest setting because you never know when you are going to take a photo (or several
) that will be worth enlarging.
Or if you find out that you want to crop the photo, if you are at the 1.1 setting you will get tons of graininess after cropping.
Like a poster said above, with the low cost of SD cards these days, it's a much better idea to leave it at the highest setting. Or the second highest at the absolute least.
The beauty of digital photography is being able to see immediately if the photo is a 'keeper'. I would come back to my room each night and delete that obviously bad photos in order to keep a decent amount of space on my card.
On our last trip, we took a 256mb card, kept the camera at the highest setting and didn't even fill the card. Came close, but we didn't. And being a photographer, I tend to be SUPER duper shutter crazy. I take photos of everything