I was thinking of how great it would be if e.g. the new PB's was equipped with trackballs instead of touchpads. Like my old Duo 280c, or other portabel Macs of the era.

Do you think it is a possible project to convert a newer touchpad PB, to integrate a trackball instead of the touchpad?

Of course, I'm thinking of an optical trackball, and the ball about the same size as in e.g. the Duo.

Is there any solutions already in the market? do I have to "build" it myself?

Any suggestions?