Put your keys in the door of the car ... You know where the keys are, but won't necessarily know where the car is anymore
Out your keys in:
A locker (there are in fact lockers at swynnerton - whether or not you can use them is something to ask warped)
with the staff behind the counter (not exactly practical at nvs)
With your friends on a retailers stall
In your gear bag, toolbox etc
On a lanyard (still loseable)
In a zipped up secure pocket - without a hole in it
Some pod belts have an internal zip up pocket