i sought out everywhere however i aren't able to find a solution anywhere, and i am a beginner with php so hopefully you will see someone so kind that helped me to. i am dealing with wordpress and i am by using this line

$post_IDs = get_posts('category_name=glicinie');

to retrieve all posts inside a category, however in this category i've large amount of replicates posts, here is a area of the array which i obtain [ with print_r($publish_IDs) ]

Array ( 
[0] => stdClass Object 
( [ID] => 761 [post_author] => 2 [post_date] => 2011-07-26 12:07:17 
[post_title] => Flower )
[1] => stdClass Object
( [ID] => 760 [post_author] => 2 [post_date] => 2011-07-26 12:04:46   
[post_title] => Rainbow )
[2] => stdClass Object 
( [ID] => 770 [post_author] => 2 [post_date] => 2011-07-26 12:03:18 
[post_title] => Coconut )
[3] => stdClass Object 
( [ID] => 743 [post_author] => 5 [post_date] => 2011-07-26 11:38:48 
[post_title] => Coconut )
)

following this i personally use this code below to populate a choose inside a form with title and year (that's a custom area from the publish) for every publish.

foreach ($post_IDs as $post_ID) { 
$anno = get_post_meta($post_ID->ID, 'year', true); 
$title = $post_ID->post_title;
echo '<option value="'.$title.'">' . '[' . $year . '] ' . $title . '</option>'; 
}

now you have often seen before which i have two posts entitled as "Coconut"..so within the list within the form i'll possess the publish Coconut displayed two times. things i want is obvously to show the copied posts (like "Coconut") only one time.. i believe i ought to create a type of check from the array prior to the foreach but i'm not sure how..to ensure that within the foreach i loop only with the ID's which have another "publish_title" value..but exactly how?

forgive my british. thank ahead of time :)

I believe this will get it done.

$got = array();
foreach($post_IDs as $i => $d)
{
    if(!in_array($d[post_title]),$got)
    {
        $got[] = $d[post_title];
        $out[] = $d;
    }
}
print_r($out);

Sorry to be late, and thanks greatly, your code labored :)

Here's the ultimate code I made use of:

<select id="flowers" name="title_post">
<option selected="selected" value="nothing">Nessun elemento corrispondente</option>

<?php $post_IDs = get_posts('numberposts=-1&category_name=glicinie'); 
$got = array();
foreach($post_IDs as $i => $d) {    
    if(!in_array($d->post_title,$got)) 
    {   $got[] = $d->post_title;
    $OUTpost_IDs[] = $d; } 
    }

foreach ($OUTpost_IDs as $OUTpost_ID) { 
    $anno = get_post_meta($OUTpost_ID->ID, 'anno', true);
    $city_autoformazione = get_post_meta($OUTpost_ID->ID, 'city',true); 
    $title = $OUTpost_ID->post_title;
      echo '<option value="'.$title.'">' . '[' . $anno . ' - ' . $city . '] ' . $title . '</option>'; 
    } ?>