I bought a two-day pass in Lyons, France for about 28 Euros. It was really worth the money. It included all transportation (at least four a day for 5.2 Euros), entrance to museums for 16 Euros, a boat cruise for about eight Euros and a walking tour through the city for 12 Euros.
I was impressed with the effort of the I in France (the I we all travellers know when we see one). I strongly suggest that all travellers see them before starting a trip in each town. In every city, except Paris, it is run by a reputable company.
I visited St. Emillion near Bordeaux, South of France,, but I felt badly. I arrived too late in the afternoon. A day pass included a discount for wine tastngs, a train ride around the village (worth it as it is a hike), a visit to the vinyard for wine and a cave visit. Yes, you can all do that in one day, if you come by 10:00 a.m.
Feeling good about the pass, I bought another two-day pass, worth about 16 Europs in Budapest, at the I. But it wasn't the real I. It was run by a company in Budapest. Needless to say, it was expensive.
Transportation is cheap and one can only travel so much in two days. The pass was only for discounts of up to 25%. Some places didn't give any. They tried to show how the card could be used to maximize it. But looking closely, if you wanted it to work for you, you had to see at least two museums, two cathedrals, eat in four restuarants, drink in two bars, soaking in a spa bath – all in two days!
Don't buy the day pass in Budapest. The place is huge and travel, even by tram, can last 30 to 45 minutes to each must-see place.