What laptop do you have? Macbook Pro's are so thin now even a RJ45 hole is too tall. I can forgive them for not having a replaceable battery for size/weight and noise reduction having everything so tightly integrated.
The ThinkPad x240 is thinner and lighter than a MacBook Pro and still manages to find space for an external battery, an RJ45 jack, and a VGA connector.
Its not thinner. The x240 is 0.8 inches thick [1] and the MacBook Pro is 0.71 inches thick. [2] Not trying to fanboy here having used both of those laptops recently.
Thanks, and sorry about the misinformation. I got my info from http://www.apple.com/macbook-pro/specs/, which was the first result for a search for "Macbook Pro dimensions". Didn't realize that was apparently obsolete info.