I have an iPod Touch and run it from the iTunes on my laptop. A family member is going to be getting an iPad 2 and the best option is to have it run from my laptop as well. Is there a way to have 2 iTunes downloaded on the same computer to run the devices separately without an attempted second download of iTunes just being an update of my current iTunes? Otherwise I'm going to have to spend some time changing the synchronization settings, and we all know how tedious that can be.

Also, would an iTunes on an external hard drive work on a computer that already has iTunes downloaded?

Any advice? If there is a way to do it, be very specific please.