For those of you who do not know what I am talking about: http://www.teamviewer.com/images/presse/quickconnect_en.jpg
Teamviewer overlays that button on all windows to allow you to quickly share a window with someone else. I would like any ideas on implementing something similar -- if you have example code, even better (specifically, the button -- not the sharing). I am interested in C++ and QT... but I would be interested in good solutions in other languages/libraries if there are any.
Thanks.