Is it possible to take the tgv from Paris to Strasburg without any connections and then rent a car at the Strasburg train station to drive 2-3 weeks through france, dropping the car at tthe Marseilles airport?

yes.

There are TGV high speed trains every half an hour from Paris Est direct to Strasbourg, you won't have any problem finding a connection to suit your plans

definitely

Very easy to do, and the car rental agencies are mostly directly across from the station.

www.voyages-sncf.com for fares and schedules and if you book far enough in advance you can get discounted but train-specific tickets that cannot be changed nor refunded - full fare tickets should always be available in Paris.

Contact autoeurope.com for car rental

If you want to stay in a hotel your first night then pick up the car the next day, after exploring Strasbourg sans car and a day of car rental there is a phalanx of hotels right opposite the Strasbourg main train station - I stayed in the bargain but good IBIS (www.ibishotels.com - part of the Accor group (www,accorhotels.com).

Thanks for all the input.

Any suggestions about where to stay for the night when driving from Annecy or Tallories to Savona, Italy, on the motorway?

Also, what is the best cell phone to use in Europe (France, Italy, Switzerland, and the Netherlands) for an American traveler?

Stay in Savona, it's only 4 hours from Annecy.

Thanks - that would work.