A great way to spend the afternoon in Paris? Grab some cheese, a baguette and some wine from the shops on the Champs Elysees and head down for a picnic in front of the Eiffel Tower!
The trolley tour of Boston, offered as an optional, is the best way to see the entire city. Take it at your own pace, but I would suggest stopping off at the USS Constitution and Fenway.
If you visit the massive outdoor club Rio, also go next door to the 'Green Pardon' which is much cheaper, and has about 5 bars and three separate dance floors - all outside. Party till the sun rises!