WP SlackSync - Synchronize Slack channels + chats with your Wordpress site
Slofile - A public Slack database with live channel & member stats
Slackin - Create your own public Slack chat community
2000 (!) Slack Groups - The largest curated list of verified Slack groups
Hamster Pad - A social network built on top of Slack
Swim - Choose a channel, join a live chatroom