You mean something like this?
http://www.newegg.com/Product/Product.aspx?Item=9SIAAD046B4553I saw some of these recently before buying a new laptop. They are functional, but they sort of turn your laptop into a desktop, and honestly the seem sketchy. Almost risky. I'm not sure about what options you have on your laptop, but I suspect that your laptop isn't going to have a mini PCIe slot with more than 4 lanes, and possibly only 1 lane. That alone kind of limits the usefulness of it.
Are you looking at a particular product?