You can print at home in any size, without things getting cut off, by using "Picasa" (free to download, by Google) if you don't already have a program.
Just tick off the "shrink to fit" box instead of the "crop to fit" box when printing.
When I print at Walmart (or Snapfish), they have a similar box to tick off. When you crop pics on your computer, they usually end up odd sizes. When you go to print at a store, if you don't give any instruction, they will end up being cut off in odd places.....
When you "shrink to fit", you can end up with pictures that are not 4x6 exactly, but they will be close (and nothing will be chopped off!)