Before Agent Harris reveals to Tony about the Phil Leotardo's plan to murder him or those close to him, we can see Tony's Escalade in the background. When then camera switches for first time to Agent Harris and then back to Tony, we can see that the white Escalade is gone, specifically, it's 'replaced' with the red Jeep Wrangler.
When Tony and Carmela are at the restaurant, the wine glass and dessert change positions several times without anyone drinking or eating. In addition, the dessert also changes colors from bright green and white to brown.
When Tony is draining the pool the pump lines are set up so the pressure line is in the pool and the suction line on the lawn. This would be the way to fill, rather than drain the pool.
In the mental hospital, AJ is seen playing an Xbox 360 without a hard drive, and the audio indicates that he is playing the game Halo (or possibly Halo 2). These are original Xbox games, and require the hard drive to play on the Xbox 360.
In the establishing shot of the Bada Bing on Route 46 near the beginning of the episode, there is an Arri CSC camera truck clearly visible on the right side of the frame. There is also a Genie GR-20 lift parked right next to it.