Considered one of the first true web 2.0 sites on the net, Flickr combines a photo sharing service with a blog. Its online community tools such as the facility to tag photographs and allowing them to be browsed has helped boost its popularity. It is estimated that over two billion photographs have been stored on the site.

While the idea of allowing your child to upload any pictures on Flickr may be worrying the website classifies every image on the site preventing under age users from accessing moderate or restricted images.

27 million