A few weeks ago I posted a question: Most Creative way to display 42. I received dozens of great answers. I loved reading them except I noticed one issue. People were editing their answers with new ways to answer the question, except I didn't receive any notifications and therefore didn't see any of their new answers. This a feature-request. When users make substantial edits to their answer, i.e. more than say 50 characters, the OP should get a notification about it.
Note: this can apply to all of Stack Exchange but I decided to post it here since its the most prevalent I think here.
I think substantial should mean 50+ characters added to the body.
If not a substantial edit, then perhaps the answerer should have the option to notify the OP of the edit, for example in a check box marked: "Notify OP of edit"