Java application to implement a Mouse using a Webcam and laser pointer

Hi. I want to implement a mouse using a webcam. I would be tracking a laser pointer dot using a webcam and converting that point to mouse coordinates. I want to develop a java application for it. I am a beginner in java so i would be very thankful if you please help me out with the following:

* How to launch a java application at startup in windows and linux?
* How to stream live video from a webcam in java?

Ok, I can only answer the first part of this question as I havent done any video streaming but I am working on a similar application soon.
Anyway, I start my java applications on startup using a small batch file which is started with a scheduled task from the task manager...
Hope that helps and I will be interested to see any replies regarding streaming