Microsoft makes a big deal out of the Surface RT's integrated kickstand. It's a well-implemented feature, but more interesting is what's beneath. The small slot, accessible only when the kickstand is open, takes a microSDXC card of up to 64 GB. You can't install apps with microSDXC cards, but you can use them for documents and media such as music, photos, and videos. Having this extra storage is important because only 25 GB of the Surface RT's 32 GB of storage is available for programs and files. Of that, Windows RT uses about 10 GB. That means a 32 GB Surface RT tablet really comes with only about 14 GB of usable storage.