I made a carbon copy of my old iMac's hard drive, sold it, and just received my new iMac last night. Is there any way to move Quicktime Pro from the Carbon Copy to the new iMac?
I don't know, but I have it on two of my machines. As long as you don't give away the code, you should be fine. It's just like OS X Single/Family packs. Apple trusts its users to get the family pack to install on multiple computers.
Ideally, you would have taken it off the machine before you sold it, but you can still use your code more than once. Apple is nice this way (at least for their typical consumer end products).