Google Maps' newish Street View feature with Panoramio photos has not yet been added to the Google Maps API. However because Street View is in essence a Flash file it is possible to embed the Flash code for the Street View with Panoramio into your own website.
Here's an example showing the Eiffel Tower,
I've created a map, Panoramio Embed, that will allow you to get the embed code for a particular Street View by just placing the map marker in the required location. Once you have found a Street View you like all you need to do is cut and paste the embed code.