Some of the Panasonic point and shoot digital cameras actually let you choose which ratio you want to shoot in (above). But this is not a standard choice for most cameras, whether is be a point and shoot or SLR.
So, what can you do to combat this ratio and cropping problem? There's a few solutions.
* You can loosely frame your images during the shooting process so that no matter what size you decide to print, you won't be loosing any important information in your crop.
* You can determine your favorite print size and purchase a camera that produces an image with that ratio, or vise versa, only print specific print sizes that match the ratio of your cameras image.
If you are printing your images yourself, then you have the ability to make the crop selection yourself. If you send your images out to be printed however, you should remember to crop to the print size you want before sending your images off to ensure that the crop goes where you want it to go. To make sure you have a proper ratio crop, you will need to have photo editing software that either allows you to input a crop ratio, or where you can turn on the rulers and a grid to follow while you digitally crop the image.
While you, the photographer, may now understand crop ratios, this is a much harder thing to explain to clients who want to order prints. Something I find genius is the way that myCapture shows the crop selection options during their print ordering process. myCapture is the service that many newspapers are using on their sites for readers to purchase photos that they have seen in the newspaper. As you can see above, they show which areas will be cropped out with which cropping selection. In addition, they offer a white border option so that the image isn't cropped at all... but with this you will see a white border if your 5x7 print is framed with a 5x7 frame. The times when you may want to choose a white border option is if you will be putting the photos in an album, a free floating type frame, or having a custom mat made for your image and frame. In these cases, a standard print size isn't usually as necessary.