Wonder where your ethical barometer kicks in. I've tried to arrange the scenarios in increasing order of questionability:

1. I need a new widget. I go down to the widget store, pick out a nice one for $5000, and pay for it with my credit card. I get the miles.

2. My buddy is excited about my new widget. We go to lunch to discuss it. The bill comes to forty bucks. I tell him "Give me a twenty and I'll take care of the bill." I put it on my credit card. I get the miles.

3. My buddy likes the deal, so we go down to the widget store and he picks out a nice one. He doesn't like credit cards, so he tries to pay by check. No dice - the store doesn't take checks. I know his check is good, so I put the widget on my credit card. The widget is in his name, and he gets the warranty, etc. I get the miles.

4. The widget store owner is now my friend. He tells me that any time anyone pays by cash, he'll put it on my credit card and give me the cash. The customer gets the widget and the warranty, I get the miles.

5. The owner is really my friend. He says he'll "sell" me a widget every week and put it on my credit card. When the payment comes back to him, he'll turn the money over to me and I pay the CC bill. I get lots of miles.

6. I force the owner to credit me with miles at the point of a gun. (I put this one in so we all know where to stop ).

OK - when does clever manipulation become cheating? How is this different from buying 100 magazine subscriptions for the miles? With a T&E card (AMEX,DC), it's expected that I will be paying for things that other people use or consume - where does one draw the line?

I just had some dental work done - I'm going to put it on a mileage-earning CC. How would anyone know whether or not you were having $15,000 worth of dental work done? (assuming you have a friendly dentist).

Where does it all end?