Vowl displays an automated slideshow of Flickr photos matching a list of tags that you specify in its preferences.
You can customize the delay between photos, and whether Vowl's window floats above all other windows or not.
If you click on a photo, Vowl will open that photo's Flickr page in the default web browser.

Poster is an application for posting photos and video to the web. Poster can send photos and videos to Flickr and photos to Facebook profiles and Facebook pages.
Poster sports a sleek design that lets you see your photos properly and work with them effortlessly. Whether posting to Flickr or Facebook, Poster takes a tailored approach that makes the most of each site's unique features.
* Flickr
For Flickr, Poster can post both photos and videos, auto-completes tags, lets you create and choose sets, groups, tag people and moderate your photos. Its All Items view lets you work with an entire set of photos as easily as just one.
* Facebook
On Facebook, Poster is able not only to post to your profile, but also any pages that you administer, making Poster ideal for anyone whose business, band or cause takes advantage of Facebook's massive user community.
* Works with Your Apps
Poster works with the photo editing and management applications you use now. Export plug-ins are available from the Reinvented Software site for iPhoto and Aperture to launch Poster with the exported files.
* Picture Perfect
Poster can even perform some tricks of its own, such as rotating and resizing photos before uploading. Its understated design, tasteful animations, support for multitouch gestures and keyboard navigation make posting your photos and videos as enjoyable an experience as taking them.