Yo, at Hopkins you can stay on campus if you would like in Reed Hall. You don't get the best accomodations (small dorm room, common hall bathroom and shower, old building) but it is convenient because you don't need to worry about transportation in the morning...you just have a few minute walk to the admissions office. It's especially easy if you would like to do the greeters program (meeting 1st years like me) the night before your interview, because that is at Reed Hall as well. Last year at my interview I thought staying in Reed was sufficient...not to mention free, but if you absolutely need to have a comfy hotel room, you may want to go for that.