(PECL memcached >= 0.1.0)
Memcached::get — Retrieve an item
   Memcached::get() returns the item that was previously
   stored under the key. If the item is found and
   cas_token variable is provided, it will contain the
   CAS token value for the item. See
   Memcached::cas() for how to use CAS tokens. Read-through caching callback may be
   specified via cache_cb parameter.
  
keyThe key of the item to retrieve.
cache_cb
       Read-through caching callback or NULL.
      
cas_tokenThe variable to store the CAS token in.
   Returns the value stored in the cache or FALSE otherwise.
   The Memcached::getResultCode() will return
   Memcached::RES_NOTFOUND if the key does not exist.
  
Example #1 Memcached::get() example #1
<?php
$m = new Memcached();
$m->addServer('localhost', 11211);
$m->set('foo', 100);
var_dump($m->get('foo'));
?>
The above example will output:
int(100)
Example #2 Memcached::get() example #2
<?php
$m = new Memcached();
$m->addServer('localhost', 11211);
if (!($ip = $m->get('ip_block'))) {
    if ($m->getResultCode() == Memcached::RES_NOTFOUND) {
        $ip = array();
        $m->set('ip_block', $ip);
    } else {
        /* log error */
        /* ...       */
    }
}
?>