The goal of HeyZap is to be the "YouTube of casual gaming" by giving site publishers a way to embed more than 6000 casual Flash games into their sites with a single embed code. Their business model (more detail from TechCrunch) is to collect revenue from ads within the games using the MochiAds ad platform and share some of that with developers. The publishers using the code don't get revenue, but get increased traffic to their sites.
There are a number of advertising networks available for mobile applications, but game company Tap Me is creating one specifically for game developers. Tap Me has launched its iPhone SDK today, with plans to support other platforms soon, including a generic API that will allow developers full control of how advertisements are included in their games. Rather than simply provide display advertising, Tap Me ties the ads into in-game actions, with brands able to be integrated deeper into games.