The dimensions are similar to the custom Tablet PC stand that I use on my desk. I found this one at Staples, however, you can probably find these at any big box office supply store. The cost was ~$24. Here's a link to the product info.
The nice thing about this stand is that it places the Tablet PC at a convenient angle to write with at your desk. For travel, I use a small folding tablet stand that I built. If you want an out of the box solution, this is one to consider.