Сохранение и загрузка масивов...

$array=array();//твой массив
$fp=fopen("filename","w");
fwrite($fp,join("\r\n",$array));
fclose($fp);

$array=file("filename");

$fp = file ("array.inc");

$number_array = count($fp);

for ($i=0; $i<$number_array; $i++) {
$line = explode ( '"::"', $fp[$i] );
echo $line[0];
echo $line[1];
echo $line[2];
echo $line[3];
}

Array(
[1101155378] => Array(
[p_id] => 1
[post] => Some text
[ip] => xx.xxx.xx.x
[smiles] => 1
[sig] => 1
[posted] => Array(
[1] => 15
[7] => 41
[12] => 8
)
)
[1101154387] => Array(
[p_id] => 72
[post] => Second some text
[ip] => x.xx.xxx.xxx
[smiles] => 0
[sig] => 0
[posted] => Array(
[3] => 5
[5] => 18
[9] => 1
)
)
[1101152356] => Array(
[p_id] => 44
[post] => Third some text
[ip] => xxx.xxx.xxx.xxx
[smiles] => 1
[sig] => 0
[posted] => Array(
[4] => 15
[5] => 28
[6] => 17
)
)
)