Then have the other party hand you a card, and you contact them or you could simply have a card with your contact info, no need to state what you do, that can be private.
Found it best not to include a phone number on the card. Half the people will call the next day and pester you for a hot tip with which they can make some fast 'n easy bucks. Don't you just hate that?
Thats why I dont carry a business card. One more thing, stating your profession can be perceived as gambler in certain sectors.