How can I go back to where I was?

How can I make a user go back to where he was after doing something with
a post.
For example, let’s assume that the user clicked a post in a third page,
and after doing something (reply, destroy and so on) with the post it
just redirect to the list.
But at this time, the user always go back to the first page because of
“redirect_to :action => ‘list’”
Is there any way to store the user’s location before performing a
function and redirect to the location after the function finished?

redirect_to :back