Is CPU mining even worth it? I would like to start mining, but my GPU isn't the greatest and I don't really want to spend the money on a dedicated rig. Is mining from my CPU (in a Linux environment) still worth it? Or will I not be able to keep up?
For the amount of time you would spend setting up a CPU miner, at minimum wage in the US you would be at a loss.

Even GPU mining is barely profitable for most people right now. It would definitely be more profitable to speculate, and even more profitable to operate a Bitcoin business. There are a great deal of people who want to use their Bitcoins for purchases.

At the current exchange of under $10:1BTC, the most efficient graphics cards are taking months to pay off their initial investment (with free electricity).