The latest Skype for Mac (http://www.skype.com) — version 5.1 — participants in group calls can identify active speakers and you can select recent called numbers stored in the dial pad.

Contact groups are now shown in on the right hand side, allowing more space in the side bar. In addition, Skype 5.1 fixes several bugs and issues, including the iSight Firewire webcam detection problem.

The upgrade is a free download. Also, Skype has started a contest (http://macte.ch/kFahA) asking Mac users to create the chat style for an upcoming version of Skype for Mac. The competition will run over three stages, each lasting three weeks. Two winners will be selected at the end of each stage: a judges’ choice winner that will be selected by our panel and a people’s choice winner, as voted for by Skype users.

These six winners will go forward as finalists for the grand prize. Prizes include an iPad 2, an 11-inch MacBook Air, an Apple TV and more.