Free Social Network Organizer: ThinkUp

ThinkUp is an open source web application that helps you analyze your activities and friends better in Twitter and Facebook (more networks to come).

It can display you all replies to a message, a stream of all photos posted or links tweeted by friends (by expanding the short URLs).

ThinkTank enables you to get detailed statistics about your activity, such as your average replies per day or how often you update.

Also, it provides insights about your followers and friends, like who's most popular or who updates least often.

Another great feature is the ability to backup all your activities and even publish a presentable list of replies to one of your questions (including integration with blogging tools like WordPress).