How about a Goofs message board?

[Trevor]

Not like MovieMistakes.com where if you post a goof that is obviously one and people pull the ring out of you because they don't agree with you, but simply one like this:

Hot Fuzz: In the car chase, the police car's knocked off door appears and disappears in various shots. 

I love spotting goofs. 

[Jack]

Space Mutiny - one of the characters gets killed, but she's alive and well in the next scene.

[DS]

Commando - One of many goofs, when Arnie drives away Sully's crashed car, the side mysteriously repairs itself. 

[Trevor]

Space Mutiny - one of the characters gets killed, but she's alive and well in the next scene.

 

I am embarrassed to admit that I personally know the producers and the director of that film.  

[Trevor]

My favourite goof of all time: the stormtrooper dinging his head on the door frame in Star Wars. Couldn't he see where he was going? 

[El Toro Loco]

In Killers From Space, when a friend of the main character's name (which escapes me) he exits from the passenger side, but in the next shot, it appears that he exited from the driver side! my most personal favorite goof of all.
in plan 9 (oh God), other than famous mic boom, the seats and controls are made from cardboard.

[Trevor]

Another famous goof: Krakatoa East Of Java.

Ermmm.... Krakatoa is west of Java. 

[Trevor]

I think it was in the film Mysterious Island where a hot-air balloon goes above the clouds, yet it's raining above the clouds. 

[The Burgomaster]

Another famous goof: Krakatoa East Of Java.

Ermmm.... Krakatoa is west of Java. 

Well, if you start at Krakatoa and head east . . . and go all the way around the world . . . you'll end up in Java.  (Sorry, I'm clutching at straws here).

[The Burgomaster]

One that bugs me every time I see it is during the wedding scene in THE GODFATHER.  Al Pacino and Diane Keaton are sitting at a table talking and every time the camera angle changes, the level of wine in their glasses goes up or down.  Where the hell was the continuity person?

Also, in THE GREAT ESCAPE, Donald Pleasence goes into the tunnel wearing dark colored socks and comes out the other end wearing light colored socks.  It might make sense the other way around (assuming his socks got dirty in the tunnel).  Do you suppose he stopped in the middle of the tunnel to change his socks?

[Ed, Ego and Superego]

The magically opening and closing gate in King Arthur. 
-Ed

[The Burgomaster]

Trevor:  everyone who contributes to this message board is a goof.  And I'm probably the biggest goof.

[Circus Circus]

In Cobra (1986), throughout the entire supermarket scene, a cameraman and a boom are reflected in Cobretti's aviators.

[trek_geezer]

In Lethal Weapon Danny Glover is driving the car while he and Mel have a conversation, as they switch back and forth on the closeups you can tell the car is obviously being towed because every time they come back to Glover the steering wheel and shifter changes positions, sometimes the shifter is actually in the Park position. 

[retrorussell]

At the end of my reviewed film BLUE EYES OF THE BROKEN DOLL a crew member is seen walking by in the mirror as the doctor visits his daughter's corpse in the bed.  Apart from that the film wasn't poorly made in a technical sense, but it still sucked.