How much can you haul? Off the shelf a bicycle is great way to haul....yourself. However, if you have more than a hand full of items you'd like to bring along you quickly realize the limitations of your bike.
The solutions to this problem are as wide ranging as your imagination. A simple rear rack and a bungy cord might be step one. Or you can add a frame bag / seatpost bag combo like my Fargo is showing above. There's also traditional panniers (front and rear if you like) and handlebar bags if your favor massive amounts of gear.
However, if your carrying capacity truly knows no limits, your left with only one option, the cargo bike. I ran into a really great example over at AACT (Academy of Arts, Careers, and Technology) a couple evenings ago. A Yuba Mundo complete with duel kiddy capacity and a monster porter rack / basket configuration.
So remember....if you think you have to have that SUV to get you and your stuff around....there's a bike for that!