Okay, I've changed the code to divs in this example, for explanation.
What we need to do is use div's to display inline elements, rather than as a block.
<div class="divLeft">First Div</div>
<div class="divRight">Second Div</div>
Is this what you are after? If you display them as inline elements, then you'll lose a lot of the block elements (such as height & width) though.
My advice is to stick to spans though.