While it is pure speculation at this point, what we can do is hope and wonder how and when Spider-Man could be introduced in Avengers 2: Age of Ultron.
Spider-Man comes in swinging in a After-Credits scene
This is a pretty good idea since we have had many post credit scenes given to us by [Marvel](channel:932254) introducing us to new future characters.
It would make sense that they could come up with something creative to subtly introduce Peter Parker/Spider-Man. And with this penchant for making post credits scenes, perhaps a good way to introduce him is having him swinging in. Obviously this next Avengers film will not be showing it's pernicious nature in New York but rather around the world. So it could prove a bit difficult to think of someway to show Parker's old hometown. Though it could be unlikely because Marvel stated Spider-Man would only appear in one other film before his own solo film, and that other appearance would most likely be [Captain America: Civil War](movie:994409).
He could be mentioned by way of a J. Jonah Jameson
This has been one that has been flowing from the internet for a while now. I mean it would make sense since recently this is what J.K. Simmons had to say in a recent interview with Howard Stern about whether he could come back.
“I just heard that we… that’s a possibility”
I heard some really good scenarios where Jameson could yell something like "Parker!!! Where are my pictures of Spider-Man!" or something like that.
The Peter Parker at school scenario
This has already been brought up multiple times, where they may show our future Peter Parker in school during the events of the first Avengers or the ones happening during Avengers 2: Age of Ultron. Though it would be ephemeral, it would enough to maybe confirm who would play Spider-Man. Though Robert Downey Jr. has already teased us with some big news coming soon, so we'll see.
Some type of recruitment scene?
I mean they did it at the end of The Incredible Hulk, Iron Man, Captain America. Why not keep it going. Get a dark room where Parker and Nick Fury discuss about joining [The Avengers](movie:9040).
So what do you think? If Spider-Man/Peter Parker were to make a small cameo, how would it happen?