I read Ninja cursors: using multiple cursors to assist target acquisition on large screens by Masatomo Kobayashi and Takeo Igarashi at the University of Tokyo.
Some displays can be very large, especially if comprised of multiple displays. The goal of this research is to reduce the amount of time it takes to move the mouse cursor to select something on a large screen.
The approach these researchers have taken is to place several cursors on the screen at the same time. They have shown that 2-8 cursors provides the best results, significantly reducing selection time but not overpowering the user with too many cursors.
The main problem with this approach was pointing to multiple items at the same time. This was solved by putting the selections in a queue and only allowing one item to be selected at a time. The item to be selected is highlighted, while any other items in the queue have a red arc around them. A shorter arc means the item is closer to the front of the queue.
They also encountered the problem of the lasso tool. They set in place several restrictions, such as "the lasso cannot intersect with an object" and "the lasso cannot be empty" to help the lasso tool work properly.
I personally do not like the "ninja cursors." While they do improve usability a bit, the many cursors distract me more than help me. Maybe this is different for different people.
A demo used to be available here, but that site is no longer accessible.
