Currently Being ModeratedJul 20, 2013 9:27 AM (in response to John O\'Connell)
You can't. iPhoto is not a mage viewer but a digital asset management application based on an sqldatabase. For iPhoto to open and view a jpeg image file it must be imported into iPhoto first. Drag the file onto the iPhoto icon in the Dock or into the open iPhoto Library window. Then you can view and edit the photo with iPhoto.