Right here goes, ive decided (for those that are having a little trouble) to do a quick tutorial to explain how to crop images for your phone using photoshop.
after selecting the image that you want grap the crop tool and in the boxes that i have circled red type in the width and height of the phone screen ie: the s700i is 240x320
Next i choosing what part of the picture you want as your phone image, drag a box round the section of the image you want, you can move the box and resize it if you are not happy with the position when you first drag it, once you are happy with the position right click in the box and click on crop (remember...no matter how big or small you make that box the proportions will stay the right size for the phone)
Right, now its time to resize it to the correct pixel size, go to the top menus and choose IMAGE-RESIZE-IMAGE SIZE (as shown in picture)
and when you get to the resize box (as shown) type in the same proportions as you did in the crop tool bar into the top boxes and make sure the boxes on the right say PIXELS, and also check that you have the constrain proportions box ticked.
and hopefully thats it, you now have the image that you want that will fit your phones screen perfectly.
hope this helps