jQuery typically uses a div ID to determine where it is going to display, so enter the name of the appropriate div ID in the plugin's 'where to display' setting. The default for this plugin is 'content', since most WP themes use a #content div. To display above the twentyten header, type in 'header'. Twenty ten also has div ids called 'access' and 'branding' in the header area. The sidebar IDs are 'primary' and 'secondary'. In a custom or child theme you could create your own div ID to give this plugin a more precise location. Other themes may use different ID names. Try using Firefox with firebug to look under the hood to see your theme structure.