URL Path Prefix for Products, Categories, Blog, Forum, etc...

Is there any way to have a prefix to help organize some of the links in the site?  I looked through all settings, and didn't find anything that fit this.  Here is an example of what I am talking about:

What I have:

http://sitename/this-could-be-a-product
http://sitename/this-is-a-different-product
http://sitename/this-is-a-blog-post
http://sitename/this-one-is-a-category

What I would like:

http://sitename/products/product-one
http://sitename/products/second-product
http://sitename/blog/article-in-the-blog
http://sitename/blog/another-article
http://sitename/category/red-products
http://sitename/category/blue-products

Thanks in advance.  *crosses fingers for a simple setting I am missing*

Is there any option on this. We are looking for something very similar. This is help our SEO.

I would also like to do the same thing without changing core code if anyone can help

This isn't exactly what you are looking for, but might provide a starting point for you.

http://www.pronopcommerce.com/hierarchical-product-url-with-category-breadcrum-in-the-url-in-nopcommerce