Continuity mistake: During the end credits, the camera is constantly circling a marble statue of the Avengers beating Ultron. Early on, there is a close-up of Iron Man's right hand, and it's empty. Later on, in a much further shot, he is firing the repulsor from that same hand.
Trivia: When all the Avengers are attempting to lift Thor's hammer, Captain America is able to move it slightly. In the comics, Cap is one of the few characters noble enough to be able to lift Thor's hammer (notable others being Storm and Beta Ray Bill).
Trivia: Stan Lee makes his customary appearance whilst the Avengers and a load of War Veterans are enjoying a get together. Thor offers a 1,000 year old Asgardian drink to Captain America, and Stan Lee asks for some.
Question: Nothing very spoilery! The pool that Thor goes to with Erik Selvig - did I miss something, or was that just not explained much? It seems like he meets Erik, then they both go directly to a mystical lake in a cave that Thor just randomly happens to know about.