When Kitty gives the boys each a Snack Pack, the chocolate pudding is Jello brand and in a plastic container. In the 1970s, pudding came in little cans and Jello was not one of the brands produced this way.
When Kelso is laying in bed before he has the I Dream of Jeannie dream, it shows his green phone is a rotary dial phone. However, when he is finished the dream and makes a call, he dials the phone as if it was a touch tone phone. There are also DMTF touch tones heard when he is dialing.