Is there an opensource way of making 'streetview' panoramas?

Well AFAIK there is currently no single Open Source solution for both of the steps to create an free Google Streetview replacement. But IMHO there are a few approaches that try to create some building blocks for crowdsourced/VGI approach on that topic:

1. Recording
   This includes the camera hardware, camera control and panorama stitching:

   • Frankencamera
   • Panono 360° cam (closed source) or Bublcam (closed source)
   • Canon Magic Latern Firmware
   • Hugin stitcher
     You might also checkout (near field) photogrammetry, that tries to create 3D representations of single objects or VideoMapping for collecting seemless informations.

2. Sharing
   If a crowd wants to share the results, you need a central platform that supports single steps (requesting, sharing single fotos, importing fotos, stitching panoramas, ...).

   • OpenStreetView very simple and seems to be outdated
   • OpenTrailView a new 2.0 version is WIP
   • Commons allows you to share/tag photos with geotags and semantics

There was a presentation at last year's State of the Map conference in San Francisco by the founder of CustomStreetView, a site that lets you use streetview imagery for adding things to OpenStreetMap (Google's licensing strictly prohibits that). You can upload your own imagery to that site. The author is on StackExchange.

Talking to him could give you some ideas!

There is also a new service, http://www.mapillary.com. As a cloud service not open source per se but totally crowd-driven, see e.g. http://www.mapillary.com/map/im/RCjKOg0pSUhwCzH6-3Dk6A, and active in the relevant OSS communities on contributing improvements to e.g. OpenCV, Neo4j and others.

Disclaimer - I am helping building this service.