Most of the digital cameras use some form of exif. Here is the list of cameras that use the accepted exif standard:
http://www.exif.org/samples.html
As for rotating the image, I don't believe thats a feature of exif. Exif is information about the image. Rotation in the camera is a feature of the camera's operating software. Many of them allow you to do it right in the device through their control panel and others provide PC/Mac software that will let you manipulate the images.
As far as php and rotating the images you would use the php gd library functions.
http://us2.php.net/manual/en/function.gd-info.php
These allow you to do virtually anything with an image that you might need to do.
Linear Mode
