TerraIM

Although I can't put that in the general version due to security precautions, it'd be pretty easy to implement on your custom build of TerraIM.

You would just have to modify the following file

http://terraim.svn.sourceforge.net/viewvc/terraim/trunk/terraim_source/src/RemoteControl.cpp?revision=1102&view=markup

You can use wxExecute (described http://docs.wxwidgets.org/stable/wx_processfunctions.html#wxexecute) to execute an arbitrary command.

-George