I'm not sure if this currently exists so I thought I'd try here first.
I've got an SPA3000 box which allows me to use my normal phone to use the Internet for calls (www.voip.co.uk). It works really well and means I don't have to have my computer on as it plugs straight in to my router.
I've also found a system tray monitor (http://www.clacy.com/sipura/) that will allow a pop-up box when a call comes in showing who is calling.
What I want to do is to be able to integrate this with XBMC so that a pop-up box appears on XBMC when someone calls.
I contacted the guy who built the monitor but said there were no plans to integrate broadcasting this pop up box to another IP address (or specifically XBMC).
Does anyone know of something else that is out there?