Near the middle of the movie when Peter Parker makes his Spidey Suit and he goes out and saves all those people so that he can be noticed, right after you see the guy in th subway singing about spider-man there is a part where he lands on a building and if you look at his eyes you can see the reflection of the World Trade Center buildings
From Yahoo movies:
Filming: Production started on January 8th, 2001 at Sony's soundstages in Los Angeles. Filming is expected to last for about four months, including two or three weeks in New York City. (6/18/01) Filming wraps this week.
That well before September 11, 2001 which would explain why the WTC is still there.
Actually the WTC part wasn't the ending, it were the beginning of the Spider-man part, it's because there were a bank robbery - you can see it on a newspaer seconds before the slip up - and the robbers tried to escape in a chopper but he webbed them between the towers. In the DVD version of the movie it is a lot more harder to see as everything as been blurred
"Actually the WTC part wasn't the ending, it was the beginning of the Spider-man part, it's because there was a bank robbery - you can see it on a newspaer seconds before the slip-up - and the robbers tried to escape in a chopper, but he webbed them between the towers. In the DVD version of the movie, it is a lot harder to see, as everything has been blurred"
The WTC thing you are referring to was actually going to be the trailer for Spider-Man. They got rid of it and filmed a new one after 9/11 happened.
I'm sorry, but how is this a slip up? The movie was filmed shortly before 9/11. Nowhere in the movie does it specify dates or make reference to the WTC attack. The events in the movie could easily take place before 9/11, or even in a world where 9/11 never happened.