For me, it's only about an hour's drive time, but it's always good to be prepared! My suggestions on what to pack (feel free to add to this list, obviously!):
Plenty of business cards, there will be networking galore
An open and engaged mind for taking in all the opportunities that will be presented for developing medicines for neglected diseases in developing countries
Inspiration, ideas and enthusiasm based on your unique perspective to share with those you meet
Comfortable shoes (always important for conferences!
For everyone that's local like me, travel mug of strong coffee for the commute