Here's a flash/video presentation about Google's AdSense that appeared on a blog I was reading. Check out the video. It's not specifically directed to SMEs. But imagine an online sales presentation that was; it would be much more effective than this.
More than 50% of SMEs have broadband Internet access, so this type of promotion/presentation becomes very feasible (set up and campaign management are another issue, however).
On another note, Google has beefed up its personalized homepage and enabled the addition of different RSS feeds. One nice feature: The arrangement of the content "modules" is very easy to manipulate simply by dragging and placing them in the desired locations on the page.