How to hide shopping cart sidebar when it is empty?

Displaying the shopping cart when the user has nothing in it is not necessary. To hide the cart in the sidebar, try the following steps.
Step 1: Edit your "/template/checkout/cart/sidebar.phtml" and look for line

<div class="box base-mini mini-cart"> 

Step 2: Add these lines before the opening div tag

<?php $_cartQty1 = $this->getSummaryCount() ?>
<?php if ($_cartQty1 >0): ?>

Step 3: Add this line to the bottom of the file

<?php endif ?> 

Thats it. You are done.