To resort
Currently, the greenest transport from Geneva airport is the public SAT bus. The next best thing is a shared transfer by minibus. Skiidy Gonzales, Ski Lifts, Action Transfers, Rolling Road, Powdercab and Mountain Bus Co all work together to ensure that there are as few empty seats as possible on their minibuses.
In-resort
The low price Balad 'Aulps Bus runs during the summer and winter seasons between Les Gets-Morzine-Montriond-St Jean D'Aulps and various free shuttles run to and from the ski lifts during the winter in Morzine and Les Gets.
Bigger picture
Great article on applying permaculture thinking to the ways we get around.