The Product Attribute Filter area can get very long.
In order to move the filter horizontally you want to remove the clear:both in the css:
.product-spec-filter .group
{
/* clear:both; */
If moved to the left side you might still need to limit your length. Drop down grouping provides a solution. I have outlined how to make the product filters a drop down below.
1) In the css you want to create a couple boxes for the new buttons (you'll also need some images - Minus.png. Plus.png):
.expand { float:left; padding-right:5px; width:15px; height:15px; display:none;}
.collapse { float:left; padding-right:5px; width:15px; height:15px; }
2) In _ColumnsTwo.cshtml (or whatever format you are using) add this simple java to the bottom
<script type="text/javascript" language="javascript">
$(".expand").click(function ()
{
$(this).toggle();
$(this).next().toggle();
$(this).parent().next().toggle();
});
$(".collapse").click(function ()
{
$(this).toggle();
$(this).prev().toggle();
$(this).parent().next().toggle();
});
</script>
3) In Views/Catalog/_FilterSpecsBox.cshtml wrap your SpecificationAttributeName in a new div with the img's
<div class="groupName">
<img alt="" class="expand" src="Administration/Content/images/Minus.png" />
<img alt="" class="collapse" src="Administration/Content/images/Plus.png" />
<strong>@groupList[0].SpecificationAttributeName</strong>
</div>
Good luck!