Google announced that you can now embed Street View or PhotoSphere imagery on your website.
— Google Maps (@googlemaps) November 19, 2014
This is thanks to a new Maps Embed API.
The API was actually released a few months ago, enabling developers to generate HTML snippets that embed Google Maps within their sites. They've just added the ability to embed Street View and Photo Sphere imagery. The embeds utilize the same viewer technology as Street View on the new(ish) Google Maps.
Product manager Ken Hoetmer says:
Lastly, since this feature is part of the Google Maps Embed API, embedded Street View panoramas are also free of usage limits. So go forth and embed!
More on the API here.
Image via Twitter