When I make a interface that's going to be cut up into a table, I use the "snap-to" guides in Photoshop 4.0 to draw the grid where I'm going to chop the image. Then I take a screen capture of that image, open it up again, and type in the sizes of the rows and columns. After I print that out, I now have a guide for both the creation of my table, and also a handy reference for just where I'm going to cut the thing up.

Note in the images above, the pieces along the leading edges are all broken up to match the rows and columns, even if they appear like they don't need to be cut up at all. This is important, because it locks the *size* of those rows and columns, otherwise your images probably won't butt up correctly. After I have this reference made up, I number my rows, and assign alphabetical references to my columns. Now I use name each of the image to tell me where it's going to go, the first image is "1a.jpeg", while the hands-on image is "4567d.jpeg". Neat, huh? Have fun out there!