I use a small script grabbed from fopen to get a ftp file since fopen is buggy when dealing with ftp:// urls with encoded path name (ie using abc%20def for example).

		$datei = fsockopen("localhost", 3128, &$errno, &$errstr);
		if( !$datei )
		{
			echo "proxy not available !";
			fclose($resultfile);
			exit();
		}
		else
		{
			fputs($datei,"GET $url HTTP/1.0\n\n");
			set_time_limit(0);
			fpassthru($datei);
		}

The result is that as fpassthru sends the info from socket the mem usage grows dangerously and so does the CPU usage (up to 75% of CPU on a P100 after sending 4 Megs). Doing a "while" with a "print fgets" is even worth (but that sounds logical at least). Another "interesting" behavior of this, is that when I don't add a set_time_limit, the httpd child which delivers the info is killed with a signal 11 after 2-3 minutes and 40-45 sec. of CPU time, even though my default time-limit is 30sec.

That's all I see for now.