One feature that has been requested for a while has been messaging between people on Curious Reef. Now you’ve got it!
You can view all messages (and homework comments and topic replies) on your Inbox page: http://curiousreef.com/messages/.
To send a message, just enter the person’s username in the “to” field on the send page. That will put your message in their inbox and send them an email notifying them that they received a message.
Hopefully this will help instructors keep in touch with their students and increase collaboration.
If you have any other suggestions for the site, use the contact page and let me know about them.