we only stayed in Nice for one day (1/2/12) and we decided to book a half day to Monaco, but also with a stop in Eze (a cute village in the middle of Nice and Monaco), and we were so happy with this decision.
overall the trip was about 5 hours and the tour picked us up from the hotel and also dropped us off at the end, to people who are really easy to get lost it was great. we booked the half day tour from viator and did not know what to expect but turned out great
be honest I am not a fan of Monte carlo but a trip to monaco to see the palace and the casino was interesting, I certainly enjoyed Eze though and wish we could stay longer there.
some pics from the trip here
http://www.lulufun.com/2012/01/monte...-day-tour.html