RSS Feed Widget

Hi I'm trying to use an RSS Feed widget in the side bar and I'm getting the following error: Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 1966080 bytes) in /home2/growthpo/public_html/wp-includes/SimplePie/Item.php on line 2736 I'm a newbie and don't know what this message means. Any ideas? Many Thanks.