Three photographs on Jack's mantel, one in his wallet, and one hidden in his bedroom.
the 3 on the mantel:
a "team photo" taken at a 4th of july picnic.
his graduation photo from the air-force academy.
a photo of cassie with the frame that she gave every member of sg-1 her first christmas on earth.
the 1 in his wallet:
a picture of the first person killed under his command. so he's reminded to never let his guard down.
the 1 hidden in his bedroom:
his son at age 6. it's a school photo & jack can't get over how much charlie looked like himself at that age.