business cards are a great way keep in contact with  people in rio, whether they are for business or personal reasons - a small plain card with one's name, company, email, local cell phone number, provider, and whatsapp number are very convenient to have on hand - these cards should be given after a long converstaion and not as an introduction.

rather than the business approach to passing out a card, it is much more memorable to be creative and personal - writing a small note on the card, perhaps with a funny line, inside joke, or a creative reminder of the meeting, is always a good idea - ensuring this interaction in relaxed is increased with giving the card after a long chat or by handing it to the individual directly.