From 22 august to 6 september, me and my girlfriend will be in the USA for a vacation. We will fly on Boston and back we fly from Philadelphia. We like to see Boston, New York (of course!) and Philadelphia. I need some advice. How many days would I stay in each city, and are there nice places to visit in the neighbourhood of this city's? We will stay in Youthhostels (suggestions?!?) and will travel with Grayhound busses. Hope to get some reactions.
Gee your questions are a bit hard to answer given the information you posted? May I ask what your travel budget is? There are many exciting things to see and do in all those cities you mentioned. Can you be a bit more specific?
Boston, Philadelphia, and NYC will be excellent places to visit that time of year. Bring warm-weather clothes mostly because it should be very hot at times. If it were me, I'd spend longer time in NYC because there is just so much to do, but it can get expensive if you're trying to stay on a budget. In Philly you should visit Pat's and Geno's to get a steak sub, basically a tradition of the city (they were invented there). NYC there is so much to do, I especially liked being in the middle of Times Square, Central Park, and the NBC Studio Tour. Other people who have been the these cities more than I have probably have better input...