OK I will chip in with my two penneth worth !
Big green button looks bright, modern and "green".
For me a big draw would be if the charging point were somewhere I was going to stay for at least a few hours eg at National Trust property where charging could be free to NT members or ask politely and hand over battery + charger on arrival, lockers in supermarkets / shopping centres like left luggage locker with a power point inside.
Interesting observation Trevor, specific destinations and public attraction places would be the key places for such a scheme.. it does raise a lot of questions about how you would charge though and the insurance side of things.. I think a lot of businesses might be reluctant because of the risk of fire or theft/damage.
We'd need to get someone with legal knowledge to explore that side of things..what I do know is, all places that are businesses or open to the public have to have public indemnity insurance by law, but I'm not sure if that would extend to covering theft or damage or accidents related to charging. So perhaps might have to clarify that people who use charge points do so entirely at their own risk and it might have to be an online registration/membership card approach, so you that proves you accept liability and businesses are protected from claims.
The other legal side of it though is, fire and insurance to business premises. Would their policies cover or prohibit charging batteries? Are there are public safety law issues or restrictions from electricity providers on such use of electricity to third parties?
We need to try and think about this more from the charge point/business side... you would have loads of random people coming with batteries and chargers you know nothing about, if they're safety approved, how much current they draw etc.. in most cases just a chat with the owner might be sufficient but a lot of places might just think, no its a load of a hassle.
These legal issues might severely limit the scope a charge point scheme, and restrict it more to friendly family business type places?