Yes, the controls simply fit the needs of the users. Some people spread them out, clustering them near the areas where they are used (like putting all of the turnout controls for a rail yard on the fascia right next to the yard). Others make some of them redundant, so various functions on the layout can be controlled from several "command" locations. Localized command centers are especially nice on large layouts where more than one person may be running the trains. Redundant controls are nice for when you're running the layout by yourself (or with fewer than the "normal" operating crew).
Another technique used by some is to place TV cameras in remote sections of the layout and control everything from one place. Some go so far as the create sophisticated and realistic command centers!
My layout is small (N-scale on a 30" x 80" hollow core door) and sits with one long side against the back of a couch; so I placed my controls in the center of the other long side (which is right next to the yard, where most of the coupling and uncoupling takes place).
I'm planning on building an HO-scale layout near the ceiling around the perimeter of my son's room. It will be very simple (one big loop with two sidings). My thought was to hang the power packs, turnout controls and block controls on one wall (maybe on a small board). The main purpose of the layout is to simply entertain my three year old son (who just loves trains!), and keep it out of his reach for a while! So simple and straightforward is the name of the game here...
-Rory
