Nearby is a square full of artists who'll sketch you. Afterwards you can wander down the hill to the vegetarian restaurant Rayons de Sante, through the street markets to the the infamous Moulin Rouge, Next door is Paris's best disco The Locomotive. The ideal place for a quick lunch after 'doing' the Sacre-Coeur. Abbesses Lovely English-owned vegetarian restaurant. You can spend all day in a caf and no one will hassle you.
Mineral water is dead expensive.
Better still, leave your liver at home and try du vin instead. Then take a big bottle of water, lots of food and your suntan oil and head west for Paris beach in the Bois de Boulogne. There is a beautiful, peaceful, tree-covered island in the middle of a large lake, reached by ferryboat for 5.50F return. Here you can sunbathe all day and enjoy a picnic. Eurodisney Kids love Eurodisney, and it can be lots of fun for serious grown ups too if you turn off your brain for 12 hours and regress to age nine.