Spaces vs. Tabs?

Mike Hall asks: "It has come up at work again. We are about to start a new design on our product and the spaces vs. tabs discussion is back. When you indent c/c++ code should all spaces, or tabs be used? Almost everyone agrees that a mix of the two is a bad idea. Currently most of the programmers here want to use tabs set to 4. I am a space junkie. I prefer all my code to look the same if I am looking at it on vi, emacs, less, or on a paper after a lpr command. What does the slashdot community feel is the pros and cons of spaces and tabs in code?" I'm kind of torn on the issue. I believe that properly indented code is important in improving readability, but I'm also a firm believer in the fact that to edit code, you shouldn't need to spend hours and hours on formatting. Tabs are the fastest way to align your data, but they have their drawbacks and formatting code with spaces takes for ever. What works best for some of you, out there?