No matter how many times you visit Disneyland your first experience after coming throught the gates is Main Street, U.S.A. The high railroad embankment prevents you from seeing the outside world as you enter the "Magic Kingdom" , and main street is just as magical as the rest of the park. Here is what Wikipedia has on Main Street:

Main Street, U.S.A. is patterned after a typical midwest town of the early 20th century. Walt Disney derived inspiration from his boyhood town of Marceline, Missouri and worked closely with designers and architects to develop the Main Street appeal. It is the first area guests see when they enter the park, and is how guests reach Central Plaza. At the center of The Magic Kingdom and immediately North of Central Plaza stands Sleeping Beauty Castle, which provides entrance to Fantasyland by way of a drawbridge across a moat. Adventureland, Frontierland, and Tomorrowland are arrayed on both sides of the castle.

“For those of us who remember the carefree time it recreates, Main Street will bring back happy memories. For younger visitors, it is an adventure in turning back the calendar to the days of grandfather's youth.”— Walt E. Disney

Main Street, U.S.A. is reminiscent of the Victorian period of Americana with the train station, town square, movie theatre, city hall, firehouse complete with a steam-powered pump engine, emporium, shops, arcades, double-decker bus, horse-drawn streetcar, jitneys and other bits of memorabilia. At the far end of Main Street, U.S.A. is Sleeping Beauty Castle, and the Plaza hub which is a portal to all the theme lands.

The design of Main Street, U.S.A. utilizes a process to give the appearance of height called forced perspective. Buildings down Main Street are built at 3/4 scale on the first level, then 5/8 on the second story, and 1/2 scale on the third.

I personaly think most of the magic happens inside the store on Main Street at night when guests are leaving the park. What better way to make the visit last a littlelonger than to take home a sutffed Mickey, a box of chocolate covered peanuts, a new shirt, a limited edition sculpture (that cost as much as a smal 3rd world country), a Disney DVD, or even one last churror. Sure most of the trinket you bring home end up in the closet, but that's not why you really got it in the first placeis it?