I am debt free like you FM (with the exception of mortgage and car loan and utilities) We have a home equity line, but we keep that paid off. We use our credit card for every single purchase we can as we get a return on doing that. Not using our credit card would be like throwing money in the trash.
What we do though is keep track of every penny we spend. We get a receipt for every purchase, no matter how small. At the end of the day I take all the receipts and total up the money. That amount is then moved from our individual checking accounts into our joint account. Our joint checking account is used solely for paying bills. When the money is moved over it is rounded up so if we make a purchase for $29.02 then we will move $30 over. Those extra cents add up over time and also build in a little buffer in case we ever mess up a little. Every two weeks I will pay our credit card bill online by paying the entire balance at that time right away. I know the money is there because it has already been moved to our joint checking account.
The great thing about doing it this way (for us) is that not only do we get perks from our credit card (GPS, two iPods, rice cooker, thermopen, and many other cool things), but by tracking the money each day we can see what we are spending on and what our spending habits are. If we starts to spend too much then we notice it right away and can take corrective action.