It is possible. Take a look at the codes below. I have created two pages set.php and title.php.
The set page contains a form where the user enters a title. When user clicks the SET TITLE button, the user input is sent to the title.php page and used as the title for that page.
<form method = "post" action = "title.php">
Enter title :
<input type = "text" size = "50" name = "title">
<input type = "submit" name = "set_title" value = "SET TITLE">
yes, as in the replies above, the title is just a tag, the tag can be written in php from a datatabase, from any of the parameters passed to the filename, from any php predefined variable, date, time
a search page, links to external sites, and use the title as part of attribution, that the content is somebody else's, the relevant sites use a similar arrangement linking our content
code_sample takes a parameter ext, external.php?ext=(urlencoded url),