Hamsterdan writes: Hey, Windows users — seeing ads in your Skype calls? Fret not, it isn't a rouge version of the software; it's just a new twist on "free" VoIP calling. Skype has today announced the launch of Conversation Ads, finally, a way to make cash off of free calls. These new display ad units will appear within the calling window of users who do not have Skype Credit or subscriptions when they're making 1:1 Skype-to-Skype audio calls using Skype for Windows. Strangely, no other platforms — desktop or mobile — are mentioned; perhaps ads are being ported elsewhere as we speak.