FotoViewr is an online tool that lets you create slideshows of Flickr Photos with some nice 3D effects. The good thing about this tool is that you do not need to sign up to use this service. It is absolutely free and without sign up.

You just require your Flickr username and select one of the slideshow style for your slideshow. It’ll ask you to select one of your photo sets to create a slideshow or you can filter your photos by tag to add to your slideshow.

Currently, FotoViewr doesnot allow you to embed slideshow in your webpages or blogs, it just provides with a link to the slideshow page which you can share with your friends. The service is in beta and they plan to provide embedding of slideshow in webpages or blogs in future.

The main drawback i found is that when slideshow is created, it requires a lot of processing and the other one is that it only selects 30 photos at maximum, out of selected photos for the slideshow. Despite drawbacks, the slideshows obtained are quite nice.

FotoViewr is also available as a Facebook application which you can add to your Facebook Profile.