I'd be interested in an open source solution for displaying our own streetview-type imagery. The county I live in is quite rural so Google hasn't yet driven our streets. In 2011 the County's public works department paid a consultant to drive the public roads in a streetview-type car. The county has all collected imagery and point clouds, but only outdated software to view it in. I've hacked together a proof-of-concept that loads the panoramic images into a web browser (using three.js) to pan around and zoom. But I haven't figured out how to overlay the road centerlines yet to be more Google-like.