As I am sure you all know by now, this photo was posted on Miss Tammy's Beatles photo blog. Kevin from WGYTTN sent me this information about the photo:
"This photo of John Lennon and Yoko Ono was taken outside the Sherman Grinberg Film and Tape Library in NY the Friday before John was Murdered. Pic was taken by the building maintenance guy in the hallway outside of Sherman Grinberg Film and Tape Library at 630 9th Ave,NYC Dec 4th 1980" James Smith
The question still remains: who is the girl posing with John and Yoko and who is the man trying to photobomb this photo?