Your behavior changes when you move from one location to another -- so why shouldn't your phone adapt, too?
Install Setting Profiles, and it can. With Setting Profiles, you tell you phone exactly how to behave based on any number of conditions. Want to have your ringer switch to vibrate-only when you're at the office, then switch itself back to ring-and-vibrate when you're at home? No problem. Want your phone to automatically text your significant other every time you arrive at the Boston airport? Easy enough. Want to have your display stay on when you're listening to music in the car? Setting Profiles can handle it all.
Setting Profiles costs $4.