In cases like that, I usually just get an enclosure such as this:

http://www.newegg.com/Product/Product.aspx?Item=N82E16817423003

This basically turns your laptop hard drive into an external one. These usually come with a USB cable with 3 plugs. Use the main plug on the hard drive enclosure and the long one on your computer. If the drive needs more power, use the extra plug for that. I've never had to do that though. I'm currently using that particular one I linked to, and Newegg is very respectable so you may want to look into that alternative.