Traditionally, users take photos on the iPhone and upload them to the computer. However, there is a way to move JPEG images from the computer to the iPhone. The solution uses the iTunes sync feature. Fortunately, this is the same feature that enables photo transfers from the iPhone to the computer. Knowing how it works will allow you to store any of your images on your iPhone.
Right click on your desktop. Select "New" from the menu that appears, then choose "Folder." This creates a new folder and highlights the field containing the folder's name. Type any text you want to name the folder. Navigate to the JPEG that you want to place on the iPhone. Click it once to highlight it, then press "Ctrl" and "C" to copy it. Double click the new folder on your desktop, and press "Ctrl" and "V" to drop the image into the folder.
Plug your iPhone into your computer using the USB cable that came with the phone. If your computer does not open your iTunes software automatically, go to "Start" in the lower left-hand corner of your screen. Select "Programs" and click on iTunes. This opens the software.
Click on the iPhone in the section labelled "Devices" in iTune's left-hand panel. This opens the iPhone's profile in the window to the right of the left-hand panel. Choose "Photos" from the list of options at the top of the iPhone's profile. This opens the photo sync options window. At the top of this window is a box near the words "Synch Photos from." If the box does not contain a checkmark, click the box to check it.
Click the drop-down menu to the right of the words "Synch Photos from" and select "Choose Folder." This opens a window that allows you to browse to any folder on your computer. Select your desktop from the options provided and click on the new folder that contains the JPEG you wish to move. Press "Synch" in the lower left-hand corner of the iTunes window. This places the JPEG in the folder on the iPhone.