The Impero Festive MeterImpero
‘The Impero Festive Meter’ keeps track of photos taken with their yellow festive scarf, each one submitted adds £10 to their charity meter. The One Pager contained a measurement slider that is pulled off really well.
This website has unfortunately been redesigned or gone offline, so I have removed the direct link to it. The screenshot below hopefully preserved enough of the design. FYI: the site was first featured on 19 December 2013.