There are some free and paid options available, Here`s one of them;
First create your bounding box.
<div class="aweberbox">
</div><!--aweberbox ends-->
and then style it by adding some styles to your wordpress “style.css file. This will style the class that you applied to the <div>:
.aweberbox {
width: 250px;
height: 350px;
background: green;
}
This creates the box below:
Next step, we need to insert the another <div> to hold the Aweber code, then we need to insert the Aweber code and use css code again to position it.
<div class="aweberbox">
<div class="aweberform">
<script src="http://forms.aweber.com/form/11/586476211.js" type="text/javascript"></script>
</div><!--aweberform ends-->
</div><!--aweberbox ends-->
and the css to change the font color and position the form…
.aweberform {
color: black;
width: 200px;
margin: 0px auto;
padding: 180px 0;
}
http://www.realbloggingtips.com/wp-content/uploads/2009/06/aweberexamplesteps.jpg
You can get the details here
Make Money Blogging - | Making A Fancy Mailing List Signup Box (http://www.realbloggingtips.com/making-a-fancy-mailing-list-signup-box/)