Lisa, NationBuilder allows you to follow people and pages within your nation. If you're following a person, you'll get email notices of any notes posted to their private profile. Posting these notes in the control panel (not on public profiles) can be a good way to communicate with other members of your team and we use this method internally at NationBuilder. We also move conversations back and forth between team members using followups, such as assigning a nonprofit customer questions for technical support by leaving a note and then marking a followup for that support. The community team then picks up the conversation from there. Followups are covered in more detail in this video - How to use Followups and Priority Levels in NationBuilder.

You can also set a page such as a suggestion box to "Who can view this page? > Intern" or above in the page settings and follow conversations with email alerts from that page. 

Here at NationBuilder, we also like chat tools such as Google Chat for one-to-one communications, Campfire from 37 Signals for distributed group discussion, and Asana for task management.