Some very lucky black cab passengers in London managed to pay for their rides with pearls of wisdom instead of cash.
One taxi roamed the streets aiming to increase the understanding of "passing things of value on in life".
The scheme was run by Remember A Charity, which aims to get people to leave money behind in their wills to charitable causes, last week.
Taxi driver Grant Vickers said: "Chatting with passengers is part of the nature of the job, and you often learn some strange things from those who travel with you, but this week has been really thought-provoking already about things that matter in life.
"People have really engaged on the whole leaving a gift for others idea, and it's a topic of conversation I might well carry on after this week - although probably not offering rides for free ... "
Charitable legacies in wills are estimated to be worth around £2.5 billion across the UK.
Remember a Charity director Rob Cope said: "We hope the film of the project we've pulled together gets people thinking and visiting our website to find out how every gift in a will, however small, can really make a difference.
"This is a campaign with a really important end goal, as without a flow of these donations many charities just would simply not exist."