I've been trying to figure out what to do for a tablet stand and came up with something that works pretty well using Lego.

Not sure what angle you want? Make it adjustable (this has turned out to be surprisingly useful.) Also, leaving the bottom front of the stand open allows for easy access to the charging, USB, and HDMI ports of the Motorola Xoom.

A front view without the tablet:

...and a side view:

One obvious advantage to building a tablet stand out of reusable components rather than buying one is that you don't need to buy a new one when it's time for a new device.