Today Skype it released version 5.3 for Mac OS X, the updated version of the program supports Lion and adds HD video call functionality. 5.3 is built specifically to work with Lion, however, it will work with any version of OS X you may currently be running on your Mac back to Leopard.
High definition calls can be made with any computer that has a built-in HD video camera, as well as any computer you can connect a HD video camera to. While Windows users have enjoyed HD video calling for a while now, this is the first Skype release that supports HD on a Mac.
You can nab the update (which is a free download) here.