Originally Posted by Airwings
I think the DiCaprio connection came around the time of Titanic.
When he first started the project, back in 1991, wasn't Michael Biehn his first choice for the lead?
DiCaprio was the only actor Cameron has ever mentioned, that he wanted in the role of Peter Parker. They even had discussions about it on the set of Titanic
Biehn has never been mentioned in any official capacity. He would have been well into his forties and way too old to play a high school kid. He would have made a great Cyclops though, if an X-Men film was made in the 90's.
Here's an old Cameron interview from '97 where he talks about Spider-Man and confirms DiCaprio:
Also, another interview from Comic-Con 2009: