diff --git a/TODO b/TODO
index 99d2d310..bf3e4e0f 100644
--- a/TODO
+++ b/TODO
@@ -1,132 +1,133 @@
 
 Python PJSIP bindings
 ---------------------
 
 - Handle UPDATE for re-INVITE
 - High level Invitation class that handles SDP as well
 - Cleanup Registration, Publication and Subscription to behave more like Invitation
 - Means to query RTP statistics
 - Handle sending and received of multipart bodies for Invitation
 - Fix high CPU usage
 - Properly decrease reference counts of pjsip_tx_data structs
 - Split up .pyx file
 - Use STUN to determine and log the type of NAT we are behind (PJNATH_NAT_DETECT)
 - Add option to use the STUN response for Contact header (default false)
 - Fix remainig TODOs for PUBLISH/REGISTER
 - Make all init_options passed to PJSIPUA attributes, set local_ip at runtime
 - Add feature to send OPTIONS method and parse the replies
 - Add ability for application to request handling of arbitrary methods such as
   OPTIONS, REGISTER and REFER, SUBSCRIBE (but not INVITE or NOTIFY...) and have it reply.
 - Registration requestion URI should be settable by application
 - Remove any DNS or lookups from pjsip (lookup is always done outside PJSIP)
 - Write API documentation
 
 Audio
 -----
 
+- Add option and command to mute the microphone (useful for listen in conferences)
 - Play a soft beep tone while on hold every 30 seconds
 - Play a beep after we closed a session
 - Play a special beep when receiving a call while engaged in another call
 - Implement Automatic Gain Control in PJSIP media engine
 - zRTP
 
 Command line clients
 --------------------
 
 Logging, based on trace_x configuration options:
  - Append PJSIP messages to .sipclient/log/user@domain/pjsip_trace.txt
  - Append MSRP messages to .sipclient/log/user@domain/msrp_trace.txt
  - Append XCAP messages to .sipclient/log/user@domain/xcap_trace.txt
  - Add timestamp and packet counters as for SIP trace for all other prorocols
  - Toggle sip logging at run time
 
 - Add key command to start a session when starting in receiving mode (c)
 - Create sip_subscribe_conference_info script
 - xcap_pidf_manipulation script
 - Publish service and status when starting/stopping rtp/msrp session script
 - Set the shell return code to 0 (success) for 2XX, 3XX and 1 (failure) for
   other codes. For invite scripts the code is based on the response for the
   initial INVITE, not for the BYE If RTP was not received with 6 seconds after
   call setup, consider the call has failed.
 - Add parameter to hangup after a number of seconds for sip_audio_session
 - Handle multiple incomming sessions (waiting for the re-INVITE)
 - Conference established sessions
 - Handle 301/302 redirect by prompting the user to accept/reject the redirection
 - Combine msrp/rtp in one script
  
 
 Applications
 ------------
 
 - MSRP focus
 - MSRP mixer
 - Conference-info event package
 - MSRP multiparty chat
 - Is-composing payload
 
 - Lookup capabilities for SIP (RFC3263)
 - Message-summary payload
 - xcap-diff payload
 - Buddylist library
 - Bonjour discovery
 - Lookup for ENUM
 - Write documentation
 
 
 Sessions
 --------
 
 - Comfort noise generator
 - Video (H.264)
 - Real time text over RTP (RFC4103)
 - Desktop sharing (VNC protocol)
 - Bit pipe over MSRP
 
 
 End-user experience
 -------------------
 
 - Mute other applications that access the soundcard on receiving INVITE
 
 
 Enrollment 
 ----------
 
 - End-point certificate generator
 - Account creation
 - UA-profile XCAP application
 
 
 Middleware
 ----------
 
 - rename lookup_srv to rename_rfc3263, add NAPTR lookup to it and pass a
   list of supported transports by the SIP library to select from (default is
   udp).
 - Configuration framework based on ua-profile event package
 - Event bus
 - Environment detection: ambient and geo-location detection
 
 
 User interfaces
 ---------------
 
 - Stand alone library
 - Command line clients
 - GUI
 
 
 Packaging
 ---------
 
 - MacOSX installer
 - Windows installer
 
 
 Others
 ------
 
 - Add doc strings to all classes and functions
 - IPv6 support
 - Survive local IP address changes
 - P2PSIP overlay