We're using some frequent flier miles for a Italian trip and would up with a 7 hour layover in Geneva on a Sunday. It's the price of not paying cash for the trip. What can one do with a few hours in Geneva.

I would walk around the lake promenades, see the flower clock, go up into the old town area around Grand Rue and just generally enjoy the ambiance of this beautiful city. If you have time, stop to eat at Les Armures Hotel Restaurant in the old town near the catherdral. Wonderful cheese fondue. See their web-site. Or just stop at one of the promenade cafes on the lake near the jet d'eau for some ice cream and enjoy the scenery!
After living in Geneva as a single gal,I took my grown kids back there a few years ago and had a wonderful time.

The airport and train station are connected. Geneva proper is one stop before (back from) the airport.

There are also buses into Geneva. You'd want the #10 to the city center, which is Place de Cornavin. From there walk down rue du Mont Blanc toward the lake (less than 1/2 mile) and there you are! Get a map (carte) of Geneve at the airport Tourist Office.
Buses :
Geneva Public Transport (TPG):
No. 10 bus (every 10 min.) to the city centre
No. 18 bus (every 30 min.) to the United Nations

Tickets can be purchased from the ticket machines located at the stops (small change required)

Bus stops at the Departure and Arrivals levels.
Approximative fares
Travel-as-you-please ticket valid for 1 hour: CHF 2.20.-
Day pass (city centre): CHF 5.-
3 hour pass (whole network): CHF 6.-
7 day pass (whole network): CHF 30.-

If going to the old city look for Place du-Bourg-de-Four, the main square in old town. It's not very far from the Pont du Mont Blanc bridge once you cross it.
I absolutely love Geneva and hope you find it as charming as I do. It's really not a large city and is very walkable.

Mollie, TPG raised the bus tariff considerably about 6 months ago. The actual prices are :
CHF2.20 for 30 min. (this 30min.ticket is new, I think.)
CHF2.60 for 60 min.
In addition, there seem to be 90 min. and 120 min.
And One Day Ticket is CHF8.00(!).

Thanks kappa.

Is there an easy way to make do without large numbers of Swiss Francs? Can i make do with Euros somehow? Changing money for a few hours is always a problem.