Microsoft Research is still upgrading its Surface product, despite there being relatively few of them in the wild as yet. This time around, the company has added the ability to draw on Surface with an infra-red pen, as you can see in the video above.
Interestingly, you can also use your hands just like before, and about 1 minute in the demo shows a user zooming and panning with one hand while holding a pen in the other. At the moment, however, it's only one app that it works with - the "Digital Drafting Table", which allows you to write in a number of colours, as well as scrapbook photos over the top.
One particularly nifty bit of the app allows you to virtually dip your finger into a paint pot, then rub it over the page. After a while, the paint wears off and the colour gets fainter. There's a similar feature for creating stamps whose ink gets weaker over time too.
If you want to try it out yourself, then you're out of luck. Unless you know a friendly Microsoft researcher. But perhaps one day some of the applications will make their way into other products from the company. We can but hope.