Tag Galaxy is one of those Flickr tools that visualizes Flickr image browsing utilizing tags and planetary constellations to show their related tags. A search for night for instance displays the related tags light, sky, dark and city rotating around the central tag. The interesting aspect of this display is that a click on any other tag other than the main tag will combine the old tag with the new tag to include only pictures that have been tagged with all of the selected tags.
Clicking on the central "star" will zoom in on that star and fill it with exactly 235 picture thumbnails. The planet can be rotated with the left mouse button and zoomed with the mouse wheel. A click on a preview image will load that image in front, another click will load information about the picture like the name of the artist, a description and a link to the Flickr page.
The Flickr page of the selected photo are loaded in a new tab on click. You can use the navigation on top of the screen to load another batch of thumbnail pictures from Flickr which replaces the old photos shown on the planet.
Tag Galaxy provides an intuitive way to browse for photos on Flickr. It does require a good chunk of system resources though to function properly. Computer memory usage went up between 250K and 400K when using the service.
The latest version of the Flickr browser displays the number of available images on top which should give you a great understanding of how the popularity of the term on Flickr. To get back to the main screen, simply click on back at the top or, if you want to start anew, on new tag at the top as well.