From Holy Mackerel Software:
TwitHaven is designed as an internal messaging system useful for sending short messages and attachments without the complexities of email and SMS text systems. Users only need to know their colleagues' names. There is no set up necessary - just log in and go. A photo of each sender lets us be reminded of who is sending the Message. Messages can be sent to offsite email or SMS locations. Links with DocHaven and CRMHaven to receive messages regarding current Projects and Client workflows. Messages are spoken out lout to save having to read from the screen. Messages can be dismissed and recalled then drilled down to make finding messages easier. While messages are designed to be a limit of 140 characters (the limit of SMS), it is possible to expand them to any length, increasing the row height to view the whole message or copy and paste into a word-processor for editing.