I've been uploading my Spain holiday photos on Google Plus as well.
Google Plus actually creates panoramic photos automatically when they detect a sequence of photos that can be joined. The stitching is quite well done. Maximum resolution is limited to 2560 pixels wide though.
Alhambra in the distant.
Tia and her husband Albert.
View from Alhambra.
Royal Chapel of Granada.
Inside the metro at Barcelona
Plaza Catalunya