Refactored the Kohana_View::set_filename() method to allow use of .phtml or other extensions besides .php

gistfile1.php

<?php
        /**
	 * Sets the view filename.
	 *
	 * @throws  View_Exception
	 * @param   string  filename
	 * @return  View
	 */
	public function set_filename($file)
	{
		// Detect if there was a file extension
		$_file = explode('.', $file);

		// If there are several components
		if (count($_file) > 1)
		{
			// Take the extension
			$ext = array_pop($_file);
			$file = implode('.', $_file);
		}
		// Otherwise set the extension to the standard
		else
			$ext = EXT;

		if (($path = Kohana::find_file('views', $file, $ext)) === FALSE)
		{
			throw new Kohana_View_Exception('The requested view :file could not be found', array(
				':file' => $file,
			));
		}

		// Store the file path locally
		$this->_file = $path;

		return $this;
	}