Oh, my apologies! I misunderstood that one. Thanks for the clarification.
OK, most of us use multiple USB ports -- one for the camera, one for the mouse. That makes this whole problem ridiculously easy to solve. Complications arise when only one USB port is available. The best solution is to buy a USB hub. Much as I despise using Wikipedia, good information on it can be found here:
http://en.wikipedia.org/wiki/USB_hubA USB hub that allows 4 devices at a time can be had for $20.00 USD. Of course, more is more expensive, less is less so. Yes, it costs, but it alleviates the headache of worrying about PS2 adapters, getting all that crud to work with a new(ish) laptop, and the inherent inefficiency involved with a PS2 connection.
Alternatively, you could find and borrow a computer with multiple USB ports -- and if you have more than one, that solves it ever more easily.
Again, sorry about the confusion.