Twitter e Json, leggere gli oggetti

[hotel_vv]

acquisire i trend di Twitter è molto facile, passarli tramite un foreach pure, ma come posso far uscire un determinato trend per stamparlo su schermo o passarlo ad una variabile tutta sua?

l'oggetto è strutturato così:

object(stdClass)[1]
  public 'as_of' => string 'Fri, 21 Aug 2009 21:01:48 +0000' (length=31)
  public 'trends' => 
    array
      0 => 
        object(stdClass)[2]
          public 'name' => string 'Follow Friday' (length=13)
          public 'url' => string 'http://search.twitter.com/search?q=%22Follow+Friday%22' (length=54)
      1 => 
        object(stdClass)[3]
          public 'name' => string '#BrutalLegend' (length=13)
          public 'url' => string 'http://search.twitter.com/search?q=%23BrutalLegend' (length=50)
      2 => 
        object(stdClass)[4]
          public 'name' => string '#shoutout' (length=9)
          public 'url' => string 'http://search.twitter.com/search?q=%23shoutout' (length=46)
      3 => 
        object(stdClass)[5]
          public 'name' => string '#fact' (length=5)
          public 'url' => string 'http://search.twitter.com/search?q=%23fact' (length=42)
      4 => 
        object(stdClass)[6]
          public 'name' => string 'Inglourious' (length=11)
          public 'url' => string 'http://search.twitter.com/search?q=Inglourious' (length=46)
      5 => 
        object(stdClass)[7]
          public 'name' => string 'Cataclysm' (length=9)
          public 'url' => string 'http://search.twitter.com/search?q=Cataclysm' (length=44)
      6 => 
        object(stdClass)[8]
          public 'name' => string 'Which Horror Movie' (length=18)
          public 'url' => string 'http://search.twitter.com/search?q=%22Which+Horror+Movie%22' (length=59)
      7 => 
        object(stdClass)[9]
          public 'name' => string 'Inglourious Basterds' (length=20)
          public 'url' => string 'http://search.twitter.com/search?q=%22Inglourious+Basterds%22+OR+%22Inglorious+Basterds%22' (length=90)
      8 => 
        object(stdClass)[10]
          public 'name' => string 'District 9' (length=10)
          public 'url' => string 'http://search.twitter.com/search?q=%22District+9%22' (length=51)
      9 => 
        object(stdClass)[11]
          public 'name' => string 'Hurricane Bill' (length=14)
          public 'url' => string 'http://search.twitter.com/search?q=%22Hurricane+Bill%22' (length=55) 

usare echo $json[8]['url']; per far uscire http://search.twitter.com/search?q=%22District+9%22 non funziona.

mi da solo un errore di Cannot use object of type stdClass as array in C:\wamp\www\ntt\index.php on line 21

qualche idea?