For business cards I tuck some in the extra pockets of the badge pouch then restock each night in my room. They are great to give to people and for entering drawings. I store the ones I get in the same pouch, but key is to write on them the significance. Are they an expert at a topic you need to know more about or did they author a paper you expect to have questions on?

Don't try to do it all, you will make yourself sick and miss more papers than if you leave the parties a little early and don't kill yourself trying to get to 8am talks every day.