In terms of my recycling habits, although I already try to do what I can, I think I'd pledge to try even harder if I was in effect "sponsoring" someone to accomplish something extreme. I myself am a runner, so I'd be interested in pledging for someone who's participating in some sort of running challenge.
Vero, I'm glad you think this might be helpful for you! To build on your idea about the signs which indicate whether the bin is full - I wonder whether an app like this could somehow link up with bins that have sensors to detect whether or not they are full. That way, the app itself could relay this information to you so you don't have to waste your time.
Gustavo, thanks for your comments! Yes, I definitely think it would be a good idea to make the app free for users. Linking the recycling bins to businesses and perhaps even allowing them to advertise through the app could be a good way to create a sustainable business plan. On the other hand, we could also create a crowd-sourced app which uses a large population of users to maintain accurate locations of publicly managed recycling bins. I suppose it depends on the type of audience we'd be trying to reach through the app.