This is a helpful article about ways to automatically insert certain content in various areas of the post, such as before plugin output at the end of a post, or just after the “more” tag.
This site is managed by Randa Clay who got tired of trying to keep track of all the cool solutions, ideas, scripts and bits of code that one day might be needed.
This is much better than searching around on Google and rummaging through my bookmarks for that thing I read a month ago. I hope you will find the site helpful as well.