Switchee devot:ee

gistfile1.txt

{exp:switchee variable="{segment_1}/{segment_2}/{segment_3}" parse="inward"} 

  	{case value = "//"}   
   		{!-- s1, s2 and s3 are empty - Show home page --}
   		{embed="site/_home"}
	{/case}
	
	{case value="#^products/\S+/\S+$#"}
	   {!-- s1 is 'products', s2 and s3 are not empty - Show single products --}
	   {embed="site/_product"}
	{/case}
  
	{case value="#^products/\S+/$#"}
	   {!-- s1 is 'products', s2 is not empty, s3 is empty - Show product cat --}
	   {embed="site/_product_cat" layout="single_cat"}
	{/case}
  
	{case value="#^products//$#"}
	   {!-- s1 is 'products', s2 and s3 are empty - Show all product cats --}
	   {embed="site/_product_cat" layout="all_cats"} 
	{/case}

	{case default="yes"} 
	   {!-- Show static page --}
	   {embed="site/_page"}
	{/case}

 {/exp:switchee}