WowPen is an optical mouse in the shape (mostly) of a pen, and is held like a writing implement. It has a wide flat base with a small wing that supports the middle and ring finger of your right hand. The right and left mouse buttons are controlled by the index finger of your right hand and the scroll wheel is rolled by the middle finger.
Though not as versatile as most optical mice on the market today - as there is no scroll wheel button click, or fourth or fifth mouse buttons - it is very comfortable to use and in certain applications is a much better device to use. When doing detail work such as drawing or art programs, it's especially useful. I've also found it's very nice to use when doing word processing and spreadsheets.
The WowPen has a much smaller base surface area than a mouse, so it's useable in a much smaller work area. It's also very compact and very portable, and would make a great addition for anyone who travels with a notebook computer. Also, because of its design you can maneuver the curser on screen by simply moving your fingers with small hand movements, rather than having to move your hand, wrist and (probably) your forearm with a regular sized mouse.
It takes a little getting used to holding it and clicking and double clicking the mouse buttons, but once you become comfortable with it your mouse will probably seem big and bulky by comparison.
I used the WowPen with a couple of various computer games like Blitzkrieg 2 and ROSE Online, and found that for the most part it worked very well (though due to the way that Blitzkrieg is formatted it requires the use of the scroll wheel click button, so in that instance the mouse was a better choice).
One thing I did discover about the scroll pen is that it does not weigh very much, and when I play music that has a good base beat, my subwoofer causes the WowPen to bounce on the desktop and makes the curser hop around on the computer screen.
Overall I like the WowPen, and highly recommend it to anyone doing art work or using most any business application; or, for anyone who is traveling and uses an external mouse with their notebook computers. In the gaming arena it will probably be hit or miss as to whether or not it works well with any given game. Perhaps the next generation of WowPen will add a couple of buttons to make it more versatile. If you can find one, get it and try it out. I think you will like it.