I recently added a PopClip extension for dialing Skype to my collection. It scans selected text for a 7 or 10-digit phone number, offering a Skype button in the PopClip popup if it finds one. When activated, it dials the first match in the selected text.
This is a companion discussion topic for the original entry at https://brettterpstra.com/2013/06/07/skypecall-extension-for-popclip