I'm not sure about CSS, but I do know that at CSA, CN and CTI they do not have skype loaded and the security settings, undersandably, will not allow you to upload software. I think you can safely assume that CSS does not have skype either. Also, the CPU's are in locked cabinets, so there is no access to USB ports to hook up a webcam if you were wanting to video skype.
That being said, we have taken a laptop and used the available, free wifi service to video skype home. The connection speed was not always very fast, but it served its purpose.