How can I make a rounded button using just CSS?

Here's a div that is styled using CSS to make a nice looking button.  You can add hover effects if you want it to act even more like a button on mouseover:

<div style="-moz-border-radius: 3px;border-radius: 3px;text-align:center;width: 200px;background-color:#FF55FF;padding:4px;"><a href="#" style="font-size:18px;color:white;text-decoration:none;">Deals & Promotions</a></div>

Here is what this button looks like: