Using Unslider (http://unslider.com) as an RSS-based photo carousel works well with Google’s Picasa Web Albums but not that well with Flickr and Tumblr primarily because of the RSS feeds. The Picasa RSS feed features several attributes that can be used to display full size images. However, Flickr and Tumblr, use standard RSS feed attributes that only display a thumbnail and description for each post.
In my Unslider test (http://the-fennells.org/unslider.html view source for the code), I pull an RSS feed based on the ftype query string. You can click through the different types of feeds at the bottom of the demo page. Each feed has quirks, but the Tumblr feed is by far the easiest to use. Flickr requires a userid that is not easily accessible. Picasa’s feed returns the best results, but the underlying code makes use of attributes outside of standard RSS tags.
Aside from the quirks of the feeds, Unslider is remarkably easy to use and has features such as responsive design and placeholder “dots” at the bottom which make it a good choice for a photo carousel. One thing I haven’t quite mastered is switching feeds without changing the url or reloading the page. I also found that the stop, start, previous and next functions require a bit more coding. (I’ll post updates as I have time to perfect the use of Unslider.)
In the end, as it always is, you’ll need to find what works best for you. As a long time user of Picasa, I’m quite pleased with Unslider’s performance. If you want to integrate Flickr or Tumblr feeds, it might work best as an inline viewer rather than a full carousel.