VNC coection without video

I'd like to use the VNC protocol to remotize keyboard and mouse only, that is just like a regular VNC session but without the video.

Typical usage scenario could be controlling a PA video system, a multimedia PC attached to a TV screen, and other situations where you can directly see the video output of the system you wish to remotely control.

I know about Synergy and many other similar solutions, but I'd like to use the VNC server that is already ruing on my PC.

I also know that most VNC solutions let you tu down the video quality or use very efficient encodings, resulting in low bandwidth usage, but why waste bandwidth/CPU/etc when you don't need the video at all.

I believe what I have in mind can be done without tweaking the server, because there is a beautiful iOS app called HippoRemote (http://hipporemote.com/) that does exactly this(*), but the client is only available on the iOS platform. I have not found any "regular" VNC client application that let you switch the video off.

(*) I have not measured the bandwidth usage of HippoRemote, so I am not completely sure that Hipporemote does not just discard the video from a regular VNC coection. Of course this would not give any real advantage in terms of bandwidth usage.