brianm (dev) ~ # cat memcached.php 
<?php

$pid = getmypid();

for($x=0;$x<20;$x++) {

    $mc = new Memcached("test");
    $mc->addServer("localhost", 11211);
    $mc->get("foo");
    unset($mc);

    $connections = `lsof -n -p $pid | fgrep -c "11211"`;

    echo "$x: $connections";
}

?>
brianm (dev) ~ # php memcached.php 
0: 1
1: 2
2: 2
3: 2
4: 2
5: 3
6: 3
7: 4
8: 4
9: 4
10: 5
11: 6
12: 6
13: 6
14: 6
15: 7
16: 7
17: 7
18: 8
19: 8
brianm (dev) ~ # cat memcache.php 
<?php

$pid = getmypid();

for($x=0;$x<20;$x++) {

    $mc = new Memcache();
    $mc->addServer("localhost", 11211, true);
    $mc->get("foo");
    unset($mc);

    $connections = `lsof -n -p $pid | fgrep -c "11211"`;

    echo "$x: $connections";
}

?>
brianm (dev) ~ # php memcache.php 
0: 1
1: 1
2: 1
3: 1
4: 1
5: 1
6: 1
7: 1
8: 1
9: 1
10: 1
11: 1
12: 1
13: 1
14: 1
15: 1
16: 1
17: 1
18: 1
19: 1