SPNbabble supports tags to help you organize your activities here. You can use tags for people and for notices.
Tagging a notice
You can tag a notice using a hashtag; a # character followed by letters and numbers as well as '.', '-', and '_'. Note that accented latin characters are not supported, and non-roman scripts are right out.
The HTML for the notice will link to a stream of all the other notices with that tag. This can be a great way to keep track of a conversation.
The most popular current tags on the site can be found in the public tag cloud. Their size shows their popularity and recency.
You can also add tags for yourself on your profile settings page. Use single words to describe yourself, your experiences and your interest. The tags will become links on your profile page to a list of all the users on the site who use that same tag. It can be a nice way to find people who are related to you geographically or who have a common interest.
Tagging your subscriptions
You can also tag your subscriptions, on the subscriptions page. This makes it easy to organize your subscriptions into groups and sort through them separately.
You can also send a notice "to the attention of" everyone you've marked with a particular tag (note: not people who've marked themselves with that tag). "@#family hello" will send a notice to everyone you've marked with the tag 'family'.