A bit harsh heading but it's going to be a real true. Guys from Development Seed released their Drupal distribution called Open Atrium. Open Atrium is an intranet in a box that has group spaces to allow different teams to have their own conversations. It comes with six features - a blog, a wiki, a calendar, a to do list, a shoutbox, and a dashboard to manage it all. It does everything Basecamp does and more. It is flexible and customizable, it is open... and most important, it is built on Drupal. So you don't have to wait for very special features to be implemented by your collaboration software provider, you have the power under your fingers and you have a control. Just look at these sexy screens (taken from Open Atrium):
As I already said, everything is configurable and expandable, bundled in one package which you need to install as regular Drupal installation. Install it and forget, no additional modules or configurations to be done. This is a heaven of Drupal distributions approach.
Well, I'm so impressed with this piece of Drupal art so that I'm thinking about giving up using OpenGoo and moving all my collaborations to Open Atrium. Try it yourself!