RickR (and others) are right about the bus: it's a great way to get around and see Paris when you don't feel like walking. Over the past year, the city has opened several bus/taxi/bike only lanes on main thoroughfares and the police are fairly vigilant about enforcement. This project has helped speed up bus service a bit, though it will never be as fast as the Métro.

You can now go anywhere on a bus within Paris city limits using just one of the "carnet" tickets, like the Métro - before, there was a complicated system of zones which often required more than one ticket for a trip.

There is an excellent practical guide to the bus system called "Le Guide Paris Bus" by Editions Prat/Europa ( image ). It costs about $10, is pocket-sized and is in French, English, German and Spanish. I can't find it on line, but I have seen it fairly recently in book stores here. Each bus route is mapped out stop by stop in both directions (a street address is listed for each bus stop). The maps include the various sights/monuments you will pass on your trip.

My favorite route is the number 29 from the Gare Saint-Lazare in the 8th to the Porte de Montempoivre near the Bois de Vincennes in the 12th. It still uses the buses with the open-air platforms at the back: riding through the center of Paris haging out the back of a bus is great fun.

Oh, and the bus is usually clean, safe and friendly.