The top left stamp is the 2008 EUROPA issue of the French post. The top right stamps are part of a mini-sheet commemorating French lighthouses, which was issued on November 12, 2007. The stamps show the lighthouses in Porquerolles and Chassiron. The stamps have a face value of 54 cent.
The stamp in the bottom left corner is part of the mini-sheet “Bloc Grands projets européens” (Mini-sheet Great European Projects), which was issued on July 1, 2008. The stamp depicts the satellite Galileo, which is intended as a global navigation system that is an alternative to GPS (USA) and GLONASS (Russia). It has a face value of 55 cent, which is one cent more than the 2007 stamps (did the French post raise the postage by one cent last year?).
Eric, thank you for this beautiful cover!