Based on the wording on Microsoft’s own Surface web site, it’s totally unclear whether or not the Surface RT can take advantage of the Surface Pro’s digitized pen. The digitized pen is a nice feature of the Surface Pro and works extremely well, though there’s not many apps that take full advantage of it’s functions yet. Curious about the pen? Check this out: Microsoft Surface Pro Pen functions
I’ve heard folks go back and forth about whether or not the pen will work and I can definitively say that it does not work. You cannot use the Surface Pro’s digitized pen with the Surface RT. It just does not work – at all.
If you really, really want a pen to use with the Surface RT, any capacitive pen will work. I have one from Amazon.com’s Basic series. The pen works, but not well. You have to press really hard to launch apps, and using it to swipe the screen back and forth feels like the screen is stuck in a monsoon mud puddle. So, there are probably better options than the Amazon pen, but frankly, the same pen works just fine with an iPad or Android tablet. Personally, I believe that the Surface RT is just not meant to use a pen. However, if you pay a little more, I’ve heard from others that the Bamboo pen from Wacom is worth checking into:
If you go this route and have success, let me know.