We've been using Skype on our Leopard MacBook since - oh about mid-October with very few problems - but there have been many sited on the Internets - mostly in relation to Apple's redesigned firewall.
Well, for those with problems, Skype has answers - in the form of a 2.7Beta release (at your own risk). Skype betas have treated us relatively well over the years so we'll be downloading and testing this shortly.
From Skype:
New in this version
Leopard compatible – if you have the latest Mac OS X 10.5 then you can use Skype with confidence.
Better video resolution – your video conversations are now set at a whopping 640 x 480 pixel
