We went Jan, 2003 with a 13month old son - this year Jan, 2004 going to purchase a fold down booster chair to stick in back pack for quick serve, outdoor sitting, and eating at hotel room.
I do not believe it will be a bother in carrying it around. be convientent - easy to clasp and very handy... Then he can be up to the table or sitting like on the chairs/ tables on the train station balcony having our popcorn, drink waiting for the afternoon parade and not sitting down below everyone looking up to the adults.