Macro Photography and Image Stacking
Photoshop CS4 has an image stacking program, that allows for combining several images, focused at different points, into 1 image with the sharpest parts of each. Another, stand alone program that does the same thing, more intuitively, is Helicon Focus. This is a 5 image stack, and you can see in the small example to the left, the 1st image in the stack at 100% magnification, and the final output also at 100%.
I shoot on a very solid tripod, use a remote release, and also find that images are sharper if I use the camera’s mirror lock-up feature.