Bring a bunch of business cards. If you collect them from people, write on the back why you might contact them again. For example if you talk to them and find out they own a MSP as well, you write that on the back, so when you get back you don't contact them thinking they were the VoIP guy you talked to. It's cool to meet colleagues in other parts of the country where you don't want to post stuff publicly, but since you're not competing, you can share numbers with them. It's nice to be able to hand them a card.
Set your out of office reply and someone else cover your phones. It sucks to have to talk time out of a conference to take a call or pound out an email. Your time there is so limited, you need to make the most of it.
Travel light and make sure you have room for swag on the way back.