Flickr is a great tool but there are so many ways to view the images located on Flickr with these exciting mash-ups, some let you browse by specific colours while others let you browse by tags.
This tool allows you to search a specific word and then pick your favourite images to return photos that are related and have been liked by other Flickr users
Related Tag Browser
Similar to tag galaxy, this returns related tags to a specific word for you to browse the images associated with each.
Enter a tag to be searched and it will return a host of related tags taht you can search and view the images from Flickr
Search for creative commons images as well as for commercial use images
Search for tags, or text and returns a huge galley of images to look through
This service allows you to search a specific tag and your results will be returned in a mosaic style, you can even upload your own.
Flickr Color Selectr
Choose a colour and it returns images of the same, you can also enter RGB values too.
Anouhter tool to browse flickr by colour
Check the most interesting pictures from a specific date on Flickr
Flickr Hive Mind
A more extensive Flickr search, using contacts, tags, and dates
If your into cameras this one is for you, you can select a specific camera model and browse the photos that have been taken using that camera.