I'm not a print user or anything, but I'm photoshop-enlightened lol. Okay, first open the image. Then crop your image by the dimensions of your screen (of your cell, duh) Select a section. Preferably, select the image in a rectangle, the longer side vertical or horizontal, depending on whether your screen is portrait or landscape. If the resolution of your cell phone screen is landscape style (where the WIDTH is longer), than cut a part where the width is longer. If the resolution is portrait style (HEIGHT is longer), then cut a part with a longer height.Then DO this:
EDIT > COPY and it will copy the selected area (remember you're using the Rectangular Marquee Tool!)
Then close the image you copied. Then go File > New, then click OK. Paste the image there (Control + C).
Next do Image > Image Size (on the menu!). Now where it says Width, put in the width dimension of your cell phone's resolution. My phone is 128 pixels x 129 pixels. The copy the image will get smaller. Select the entire resized/cropped image, then go to EDIT > COPY (merged) . If you are ABLE to copy merged, then copy merged -- it's recommended, only if you are able to do so.
Next, click File > New and then make sure the width and height are the EXACT dimensions reflection the resolution of your CELL PHONE screen. Once you have that, paste (Control + V) onto the blank document. Now move the image either up or down, or left or right. And there you go!
Hopefully everything I said was coherent. I don't know how else to explain it.