And don't miss the SmartPhone/PDA/Blackberry app called nanika.net/metro

It has one database called "Paris bus" that will get you from here to there with a minimum number of transfers.

Bookmarking...Thanks all, great details especially re: bus routes. EJ

Thanks to all for your replies/suggestions.

We will certainly keep the busses in mind but my 4 year-old daughter is really looking forward to riding the "underground train" in order to get around (nothing even close to to that here in Orlando).