афаик...
fputs ($fp, "GET http://www.somehost.ru HTTP/1.1\\r\\nUser-Agent:Opera/6.0 (Windows 3.11; U) [en]\\r\\nHost: www.somehost.ru\\r\\nAccept: text/html, image/png, image/jpeg, image/gif, image/x-xbitmap, */*\\r\\nAccept-Language: en,ru\\r\\nAccept-Encoding:deflate, gzip, x-gzip, identity, *;q=0\\r\\nReferer: http://www.another_somehost.ru\\r\\nConntection:Keep-Alive, TE\\r\\nVia: 1.0 ce550\\r\\n192.168.0.1\\r\\n\\r\\n");