Wordpress question
 

Is there a plugin or some other simple way of automatically inserting some code to a post? I have seen mighty adsense for inserting adsense code, but I need something I can use for different code.

I want to add an ad banner to the bottom of every post I have on some mainstream blogs.

if it is something you want to insert on every post, just edit your index.php in the theme you're using and add the block there; that way it will display in every post.
No plugin needed

maybe this helps: Quick Tags

Ahh, that makes sense. Duh. I figured there was an easy way to do this that I was completely overlooking.