The X201T offers a Wacom Digitizer which allows you to do precise handwritten notes and draw sketches. There are different versions of the X201T, some only have digitizer input only and others have digitizer + multi-touch input.
The technology on the X201T is Wacom based. N-Trig is a competing technology that has it's advantages and downfalls. From my experience Wacom has better "line quality" and the digitizers feel better. N-Trig does win at not being as erratic on the edges. But if I had to choose a digitizer type that I like more it would be Wacom. (N-Trig demo 1, 2)
If your X201T has multi-touch then you can use your fingers. The X201T's multi-touch technology supports up to 2 touch points, and it also supports the Wacom digitizer (usually referred as "penabled").
The digitizer has some neat technology built in. This is not a "stylus" because the digitizer is an "electronic device". A stylus is nothing more than a stick, the digitizer is very different and enables a few extra features. Some of these extra features are: pressure sensitivity, "hover" state recognition and palm rejection, and multiple buttons. Wacom pens may have 2 buttons and a pressure sensitive eraser.
The default X201T digitizer is known as "ThinkPad Digitizer Pen (41U3143)". This is the pen that is also used in the X60 and X61 tablets. Of course you can get other "Penabled pens" which work just as well and may be more comfortable.
The system does have palm rejection technology. When you draw the digitizer's tip or eraser close to the screen the finger touch is disabled, and will continue to be disabled while the pen is close to the screen. Once the pen is out of that "hover" state then multi-touch is enabled and you can use your fingers. It's pretty neat stuff.
Wacom digitizers are very good at pressure sensitivity. Just like "real pens" the line boldness/thickness will depend on how much force you apply to the pen. Pressure changes allow you to draw more "natural" lines. Pressure sensitivity does not work on all programs. MS Paint does not have pressure senstivity, but Windows Journal does. You may have to update your Wacom drivers.
These touch features make it very different than touch only tablets like the Apple iPad. The iPad and many Android tablets use "capacitive" screen that only accept finger touch. Capacitive pens emulate finger touch and therefore are not as precise, do not offer "hover state", pressure sensitivity, and palm rejection. Some Android tablets like the HTC Flyer, Lenovo ThinkPad Tablet, and Samsung Galaxy Note offer digitizer input via N-Trig or "S-Pen".
2 BUTTON DIGITIZER (FUJITSU LIFEBOOK PEN)
The default X201T digitizer has 1 button which by default is used as the equivalent of a mouse's right click button. There are other Wacom based pens that have 2 buttons. With 2 buttons you can do a little more with your tablet.
Fujitsu has a digitizer for their tablets that has 2 buttons and the name of it is Fujitsu LifeBook Digitizer. Having 2 buttons is better than just having 1 button.
A few other notes on this digitizer is that it looks good, it's comfortable, offers a round eraser with softer spring, and can be tethered with a string. This digitizer will not fit in the X201T's digitizer port, and it does NOT offer a pen clip.
If you update your Wacom Tablet PC drivers you will have access to more features including button reprogramming. You can make one of the buttons launch something, or be used for a specific function.
One thing I would love to see is digitizer button adaptability. Basically the digitizer would adjust the buttons to suit the program being used, or at least change functions based on the screen orientation. But it doesn't do that so it's just a little wish of mine.
If you often use your X201T as a tablet I highly recommend getting the Fujitsu LifeBook Digitizer. The default digitizer may feel limited but the LifeBook Digitizer doesn't feel like that. The digitizer gives you options to improve your tablet experience.