How do I post a photo on a Facebook wall? I see I can upload a photo but that goes into the Photos area and doesn't show up on the wall itself.
Click the 'Photo' button above the wall and select 'Upload photo/video'. As for viewing, the user may have set his/her settings on the Wall photos album so that only he/she can view them.
If you go onto someone's wall, hit "upload a photo"; it will appear on their wall.