7 hour layover in Paris

Are your bags checked through? Heck, I'd do it. Two hours in Paris beats the alternative.

You could take a 20-minute bus ride north to the medieval walled town of Senlis.

So - any suggestions on what to do at CDG during a long layover. We arrive (Continetal from Newark) at 9:30 and our next flight departs at 1:15 (AF to Prague). Any suggestions on where to eat. Any way to buy (charm?) my way into a 1st Class lounge?

I don't think you have enough time. By the time you would get processed through and were able to leave, then spend the time to get into town, it would be time to head back. You have to allow a lot of time at CDG.

It pains me to say so but you don't have enough time. You'd have to clear customs to leave the airport and then clear security upon your return. This coupled with the fact your flight will of course land on time at 0940 (much laughter here) and it's at least 40 minutes into town...well. Can it be done Yes. Should you do it, No. Sadly there are no shower or short term sleeping facilities at CDG but the wine is good and the food is decent.

Bronwen, you don't actually have such a long connection time, really. If your flight is on time, (if), by the time you get through passport control it will be close to 10:30. Your next flight leaves at 1:15 and you'll need to check in for that one at least one hour ahead. (Is it from the same terminal?) So that means 12:15. You will have at most, 2 hours, which can be spent having a snack or browsing the Duty Free. If you are determined to spend some time in a VIP lounge, you can pay your way in. Google VIP Airport Lounges. Waste of money, though, but it's your money.