After four years of existence (it was launched in February 2004) Flickr has become the most popular online photo sharing website, with over two billion pictures hosted on their servers. Flickr has evolved a lot during these years, from the early beta stages to a social networking community that has grown around photography. It has also survived Yahoo's acquisition, along with some slight changes in design and functionality.

As regards the latter, you can now find a handful of software tools that have been especially developed to work with Flickr, either to make image uploading easier or to make use of their massive photo catalog in some creative way. So if you're looking for a faster way to upload your pics to Flickr or want to download entire sets in one click, have a look at the list of Flickr tools we've prepared for you:

• Flickr Downloader - Download photos from Flickr and create Flash slideshows with them
• Flickr Viewr - Browse Flickr pictures without even opening your web browser
• Saleen Flickr Downloader - Download, tag and rate pictures from Flickr
• Flickr Uploadr - Publish your photos to Flickr in an easier way (also on Mac!)
• FlickrDown - Batch download photos from Flickr, as many as you want!
• Flickr Wallpaper Rotator - Download Flickr photos and use them as wallpapers
• Flickrfox - Browse Flickr photos from a sidebar in Firefox
• Foldr Monitr - Automatically upload to Flickr any photo you save on a given folder
• SendTo Flickr - Use the Send to context menu to publish pictures to Flickr
• Picasa2Flickr - Upload images to Flickr right from Picasa