We are flying into Charles de Gualle airport and have a 20 hour layover. Is there anyplace to locker our luggage so we can do a quick city tour?
There are no luggage storages areas as CDG, but there are at the Gare du Nord train station. You can get there by the regional train system, the RER, which has two stations at CDG, then head out across Paris from there.
Adding on to the post above, here is the Rail Europe site's page about the Gare du Nord, which gives information about getting to/from Charles de Gualle and also about the baggage consignment.
http://www.raileurope.com/us/train_stations/parisgarenord.htm
Could you maybe check those bags through, or check them when you arrive? Like many I prefer not to check bags, but if it's an option it just might be worth doing it in this case. It would realy free you up.
If that seem like a good idea, the place to ask is your airline.