How do I move the text in the widgets' header? I'd like some padding on the left side.

One way is with a CSS Insert. Look at the source of the page and locate the widget. For example you might see this

<div id="polls" class="widget widget_polls"><div class="widget-title"><h3>Polls</h3></div>

In this case you would use the following CSS Insert

div#polls h3 {
	margin-left: 20px;
	}

where 'polls' would be the widget ID in question and you would adjust the 20px to what ever you want.

ok, so there's no possibility in the theme options to make a general adjustment, for instance under Widgets --> Widget Title Box?

Sorry, I had it in my midnd that you wanted to do this for a specific widget. To do them all just put

margin-left: 20px;

in ATO->Style WIDGETS->Widget Title Box

Thanks JD. It didn't quite do the trick, because it pushed the whole heading, inlcuding the background, to the right, but then I figured out that it must have something to do with the padding and so I inserted

padding-left: 5px;

and that worked!