Barry posted earlier about the reported Google-eBay AdSense and "Click to Call" deal. The press stories were somewhat vague and incorrectly implied all elements of the deal to be international only. I subsequently got some clarity from Skype on the implementation. The big deal here is that this is PPCall coming to both Skype/eBay and Google in a potentially big way.
The "Click to Call"/PPCall piece of the deal is U.S. only, to be implemented in mid '07. It will then go international after that. Google and Skype are opening up both of their voice clients to PPCall -- it's really about accelerating adoption of PPCall. Whether there will be cross-distribution of advertisers remains to be determined, but I would assume yes eventually.
Here's a longer post on specifics of the PPCall piece of the deal on my blog.