Take your source code to a notary and stuff it into his/her safe (and pay a pretty raeppli for it). However, know that all anyone has to do is make one tiny change to it and they can now have a copyright on that. Patent it in the US if it's really valuable. Only place you can.
Just stick a copyright notice on it. But in reality there is very little you can actually copyright... you can't copyright an idea and most software packages consist mainly of common algorithms and techniques. And by the time you have going through the courts it will be of little commercial value in any case.
I take it that robBob wants some monetization of his software...if he distributes it willy-nilly with a (c), then the minor change is easy, and all he gets is kudos.
Actually I forgot why companies copyright software, especially when it's not open source. Even if it's open source (but not free source) there's still very little one can do to protect misuse as first you have to find out that someone is using your source against your consent.
As others have mentioned, copyrighting software is easy and cheap.
Sadly, it is contesting the copyright when someone infringes it that is expensive...
Copyright is usually invested in the creator automatically, you just need to a) tell people it's yours using a copyright notice and b) have an infalliable method of proving datestamp. This can be as simple as registered posting a sealed copy to yourself (and keeping it sealed), or lodging with a lawyer.