Default Powered By HTML
By default, the website builder will insert the default "Powered By" html directly after the copyright component in your theme. If you'd like this to be somewhere else, you can put the powered by div wherever you want in your html document.
You can put whatever html you want inside the powered by div. Here's an example of an alternate design for it:
<div id="powered_by">
<a href="http://mywebsite.com">
<img width="16" height="16" src="" />
</a>
Powered by
<a href="http://mywebsite.com">Jigsy</a>
</div>
It's possible to put the powered by html into your theme directly with your own html. If there is no powered by div in the theme, the website builder will insert this after the copyright component.