Photonic

Photonic is the first full Flickr client for Mac OS X. You can search and browse photo streams, from your sets and groups, marvel at Flickr's daily Explore selections, explore your contacts' photo streams and favorites and more!

When you find images you like, you can flag them as favorites directly within Photonic. After browsing photos of others, you can also name, tag, describe and upload pictures of your own to Flickr, adding them to sets and groups in the process.