>Has anyone found an easy way to stop users from making illegal copies of your software apps?
>
>My solution is to copy the CPU id into a database during the registration of my app.
>
>Does anyone know how to get the CPU id of any pc?

It's not a feasible approach; the CPU ID is only implemented on Intel's Pentium III processor, and it can be disabled by the user; disabling is normally done in the BIOS, and most do this as a default action during POST.