I personally want to install a roof rack for hauling just about anything. The plus is that it frees up my hitch and bed to be used for other things. Plus a roof rack has many choices for hauling any kind of gear imaginable. Working on ordering the track now and installing my rack from a past vehicle to my new/2012 ridgeline. Love this truck.
Roof racks are good for kayaks, if you don't want to use a trailer. The racks with baskets are also really good for smelly clothes if you secure a net over them (or, if they REALLY stick, skip the net and go buy new ones!).