When in the flexigrid list view, I thought it would be nice to have "All" as one of the options in the items_per_page drop-down.
Here's how I did it by hacking one line of code in list_template.php.
In config/grocery_crud.php add an option of a million items per page, for example:
$config['grocery_crud_paging_options'] = array('10','20','50','100', '1000000');
Then around line 139 of assets/grocery_crud/themes/flexigrid/views/list_template.php change
<option value="<?php echo $option; ?>" <?php if($option == $default_per_page){?>selected="selected"<?php }?>><?php echo $option; ?> </option>
to
<option value="<?php echo $option; ?>" <?php if($option == $default_per_page){?>selected="selected"<?php }?>><?php if($option == 1000000){ echo 'All'; } else { echo $option; } ?> </option>
It's not elegant, but it adds just a bit more functionality to GC.