We used to make our application configurable. I'm underwhelming this a lot - we used to make EVERYTHING configurable. Every time we needed to make a call one way or the other, we passed. I think this was partly because the application is used all over the world, and no two countries/provinces/states/etc. do things the same way. It's also partly because we had no real idea how the product was being used in the real world. Even if we did, it was very difficult to find anyone who would admit to being a product manager, and who would take the risk of making a call.
Things are a little better now, in terms of knowing what's going on out there. We've actually done some research into who's using the product, and what they're doing with it. It's still hard to find someone to make a call, though. Don't leave decisions like this to the developers. They'll either take the easy way out, or they'll make it configurable.
Whatever you do, don't leave it up to the users to decide.