Having been a second-line manager for many years prior to staying at home FT with my daughters, let me try to provide some thoughts from management's perspective that might help you out.
1. A raise is merited when an individual expands her job scope, performs above and beyond her peers and / or is a "high-risk" employee -- meaning that the company does not want this person because it would be a tremendous loss to the team. Think *honestly* about whether any of these descriptions applies to you and then make a list of your supporting points.
2. A cost of living argument -- *particularly* in this economy -- is a rather weak argument and I'd avoid it. Really? The only reason you deserve a raise is bc the cost of living has gone up? Not because you are a great worker? Skip this; everyone is feeling the pain right now -- including your boss.
3. Assuming that you have a positive relationship with your superiors and direct boss, a friendly, non-confrontational discussion on salary is always an ok conversation to have. Use your instincts and don't get argumentative or defensive. It all depends on when you've last received a raise, what your company's policy is regarding raises and whether they are in a freeze right now. My recommendation is to make your points but be open to hearing that it isn't going to happen right now. If you can, communicate that you understand in a positive manner. A boss really appreciates someone who helps them out in this type of situation rather than causes them more stress; because as often as not, the boss would like to give a raise but can't.
4. Assuming that the raise isn't goign to happen right now, shift the conversation in the following directions: "Can you give me feedback on whether or not I am on target to get an increase when the economy gets stronger?" "Is there more you'd like me to be doing?" "I plan to continue to work just as hard as I currently am and I'm committed in the long-term to the success of this team so I know that eventually an increase will come. Can you help me by providing feedback and guidance on my performance so that I will be in a good position to get an increase down the road?" etc.
Good luck with this!