I am fine with anything that will discourage "casual" pirates, ie borrowing a friend's disc to install it on your comp and then try to either burn the DVD or something like that. So, CD keys, CD checks, and measures to prevent simple copying of the CD/DVD is fine by me.

Anything more complicated than that is just too much trouble. The fact is, the reason why PC gaming is so distinct from console gaming is because the PC is an open platform. Fans can create mods and change content with or without the blessing of the developer (ie developer released mod tools). That same manner also makes it easy for any determined cracker to get out a cdkey generator, a cd check bypasser, or anything else like that. Unless game companies somehow find a way to make it impossible for you to alter the game files or the files on the CD (which then, I will promptly finally buy a console for the first time), all anti-piracy measures will fail.

There are absolutely NO games out there, regardless of how stringent their copy protection is, that doesn't get released by the pirates in a week after the release. Odds are, the pirates will release the game before the official release simply because they may get access to reviewer copies or have inside sources at the fabrication factories or somewhat (which was how Fallout 3 for XBOX 360 got leaked like 2 weeks before its release)

Just to throw it out there. Apparently, the games released by Valve which have to use Steam have some of the lowest piracy rates out there even though they're hugely popular. Maybe some form of Steam would be the way to go?