A small British company is selling a mouse adapter, developed by IBM, that <A HREF="http://news.zdnet.com/2100-1040_22-5617830.html?tag=zdnn.alert">compensates for trembling hands</A> and could help 3 million people in the United Kingdom and many more worldwide. After deeming the device noncommercial, IBM licensed it to niche electronics company Montrose Secam, which will now sell it for 65 pounds ($124). The device, which plugs in between a mouse and computer, filters signals to remove erratic movements such as those experienced by people with Parkinson's disease or hereditary disorders such as essential tremor.