One of my current research projects is experimenting with new ways to collect and aggregate people's perceptions of walkability. We're interested in methods that are quick, reliable, and spatially linked to the areas that people know and walk, not standardised buffers around their home addresses.
If you're from Sydney, you might be interested in adding to my data collection via this 10 minute airbrush-based survey: http://map-me.org/sites/en/sydneywalk
If you're not from Sydney, you can pan around and put in data for anywhere, but I probably won't have substantial enough data for any other particular place to use it for research at this point.
Initial data from some of my students showing their current and potential walking neighbourhoods