Lockr

Lockr is a useful add-on for Flickr that allows users to restrict access to their photos for friends and family without requiring them to register or login to Flickr. This makes it easy for people to share their content with their close ones without having to worry about maintaining copies of their social networks on third-party sites.

One of the major advantages of Lockr is that it separates social networking information from content sharing, providing a universally accessible address book for maintaining a single copy of a user's social network. With Lockr, sharing personal content online becomes a hassle-free process, thanks to its access control scheme that makes it easy to control who can access what content.

Sharing personal content online is not always easy, and many content sharing systems come with several drawbacks. Each system has a different way of providing access control, which cannot be used in other systems. Moving to a new system is often a lengthy process that requires registration and the invitation of all friends to the new system. Moreover, the rules for access control are complicated and become harder to manage as our network of online friends grow.

Thankfully, Lockr addresses these issues by providing a simple and robust access control scheme that simplifies sharing personal content online. Lockr's universally accessible address book allows users to maintain a single copy of their social network, while its cross-platform addon works on Mac OS X, Windows, and Linux.

To use Lockr, all you need is Firefox version 1.5 – 3.0.* installed on your system. Overall, Lockr is a must-have addon for Flickr users who value security, privacy, and ease of use when sharing personal content online.