Consider the computer mouse, and you will be one of the few. After all, it's just a mouse. Now consider that a mouse ships with every single PC. Dataquest estimates that 120 to 150 million mice shipped last year, a market worth roughly $1.5bn (£0.99bn). Most of the units -- up to $800m worth -- were shipped with PCs. But the real money comes from after-market sales, where manufacturers can get about $30 per unit. "Companies like Microsoft and Logitech have been the leaders in this category and they have done a good job in making mice more reliable and useful," said Dataquest vice president Martin Reynolds. "But enormous innovation is not typical of this market." If anything, baby steps dictate this market. But even minor steps can have major effects on users. Simple innovations -- such as a scroll button for browsing -- can make a user's life easier and more productive. Last year, Microsoft introduced the optical mouse, which has proved popular among consumers. Optical technology captures digital images as the mouse or trackball is moved, allowing for more precise and faster location information to the PC. Although the company refused to provide sales figures, Christine Kerr, product manager for Microsoft's mouse line said: "Optics are the future, and we know this because units have been flying off the shelves." Apple Computer has also been rumoured to be working on a new mouse -- also based on optical tracking technology -- to replace its unpopular puck-like mouse. The new mouse will allow users to register clicks by rocking the mouse. What do you think? Tell the Mailroom. And read what others have said.