BMW could be about to change that though. Using a technology known as Near Field Communication, BMW's key of the future could take the humble car key towards the sort of utility now expected of today's cell phones.
Near Field Communication (NFC) is the name given to short-range, high frequency wireless communication technology. It allows communication between an 'initiator' and a 'target'. The initiator sends out a high frequency signal, and when the target comes within range the initiator recognises it and performs the required action.
You may already be familiar with NFC technology, as it's beginning to filter into the world of mobile payment, where users can pay for goods and services with their mobile phone rather than requiring a credit card or similar.
BMW's key could have the same uses. Using NFC, you could hold your key near a compatible device to pay for shopping, book a hotel room, buy tickets to an event... virtually any scenario where you'd normally pay by cash or use a card. Unlike cash and cards though, NFC would allow your BMW key to be used in other situations too - your car key could also be your house key. You'd just have to take extra care not to lose it...
According to Jorg Preissinger of BMW Group Research and Technologies, the motivation is simplicity: "The BMW driver today already carries his key with him, so we want to enable the BMW key with an NFC interface to enable new features and services for the customer outside the car.
"With a BMW key he can do contactless payments, he can access information about the car service from a mobile device for example if it is locked or unlocked".
It looks to us like the days of picking up your keys, wallet and phone before you leave the house could be numbered... soon they'll all be the same thing!