I totally agree with the value of an in-office messaging system for all of the uses above. We use Google chat which is also free. And no, these things are not HIPAA compliant so we are sure never to discuss private or identifiable patient information.
E.g. I send a message "we need the CT on this patient". They call and have the radiology report faxed, and it is in the chart (or in Updox) quickly.
