Custom mouse?

Say I wanted to design and build a mouse with an arduino at its core (for processing various IO stuff). How would I go about standardizing the output from the custom mouse so that it would work as a plug-and-play mouse? The intranets gave me HID as my answer, but I was wondering if anyone can give me specific help (the documentation I found wasn't exactly helpful). If it matters, I'm talking in terms of WINDOWS here.

V-USB

here is an example of HID keyboard:

I am not sure if it can easily integrate with Arduino style programs

Interesting stuff. This is probably exactly what I was looking for. I would assume that arduino's AVR chip would allow it to work with VUSB regardless of the high-level coding used to program it (after all, the Arduino code is just a shiny candy-wrapper of the relatively ugly AVR code intended for these chips, right?).

Thanks

http://code.rancidbacon.com/ProjectLogArduinoUSB

I believe the latest Teensy can act as a mouse...
http://www.pjrc.com/teensy/