Just thought I would describe my experience at the MBA Tour event in DC yesterday.
Location: the tour was held at the DC convention center, which is a really nice facility. It would have helped to have some signage on the outside of the building in order to direct attendees to the right area, but I just looked for young people wearing suits and I was fine
School presentations: I arrived later than I hoped to, so I was only able to attend Emory's presentation. The speaker did a good job of dedicating most of the time to questions, which were general enough to be helpful to all the applicants. (By the way, don't worry if you can't get there right when the event starts--the registration table was open hours after the official start of the event.)
Business cards: Not necessary! When we signed in we received an ID with a bar code. Each admissions representative (whether at a school presentation or at one of the tables) would then scan the code to register our attendance. I'm sure schools wouldn't mind it if you offered your business card, but if you don't have any on you I think you'll be fine.
Dress: Most of the guys were either in suits or in slacks with a blazer on. If you weren't wearing a suit or blazer, you would probably stand out. (Can't speak for the ladies since I know nothing about women's fashion!) My recommendation would be to wear a suit if you can--may as well put your best foot forward since this will be your first impression at a lot of these schools.
Free admissions consultations: I noticed in the pre-event email that a couple admissions consultants were offering free one-on-ones. I spoke with a consultant from AdmitAdvantage and found it very helpful. Try to reserve a spot ASAP if this is something you're interested in.
Visiting schools' tables: this was the most valuable part of the event (along with the free consult). Each school had a table with promotional materials. There was an admissions representative at each school I visited, but some had alums as well to answer questions. As you might imagine, there was a long wait to meet with schools at some tables (especially MIT and Columbia), but you could learn a lot from other students' questions. Alternately, some tables were getting very little traffic. Meeting face-to-face with adcoms can seem intimidating, but they were all friendly and willing to answer questions. Be confident, likeable, and very polite, and you'll be fine.
Overall: Even though I'm not planning to apply to MBA programs until 2019, this event was a good way to meet with a lot of schools I'm interested in. The fact that it's free is also nice. I think applicants should make use of all the opportunities they can to meet with school representatives in person and express their interest, since it shows that you really care about attending the program.