It was a long time coming, but back in February Skype made it onto Windows Phone... in beta. Now, testing is over, and you can get your hands on the full, official version from the Windows Phone Marketplace.
Unlike the beta, which recommended that the app would work best with particular phones, no such caveats seem to have been put forward for this official release. As ever, the charms of video and voice calls over Wi-Fi or 3G are hard to turn down — so cheap! — and it looks slick too. You can download the app here. [Skype]