[blacksmith_tb]

Not sure if you mean on the hardware side or on the computer, the Teensy is a family of small dev boards which are easy to work with in the Arduino IDE, and can emulate USB HID devices (including mouse and/or keyboard) [1]

1: https://www.pjrc.com/teensy/td_mouse.html

[steaminghacker]

thanks for the link. I'm actually looking for any open source software that would turn, say a webcam, into a mouse.