I can tell about Microsoft Touch Mouse (last mentioned in the article) first hand. I've been using it for about seven months, and sometimes it is annoying. Idea is great - multitouch mouse, but implementation is shaky. I'd like to call this bug "unintentional scroll".<p>Since its surface is touch-sensitive, it is really easy to perform unwanted tasks like scrolling, when just moving it or clicking. For example, when holding Ctrl and trying to click a link to open it in new tam, you should be really accurate. If you're not (I'm often not) it starts scrolling and with Ctrl it just zooms in and out web pages.<p>You can get used to it, but it happens from time to time anyway.<p>On the other hand, Microsoft Arc Touch mouse ir an awesome portable mouse to keep in your bag. It takes time to get used to it, but when you do, it is awesome. It fits anywhere, because of its design (flat, when switched off). It is light. It is wireless.