VH Multi Camera Studio can be used with IP cameras that broadcast using RTSP protocol. Please note that the program doesn't seem to support cameras using h.264 video.
How to use RTSP IP cameras in Skype:
- Download and install VH Multi Camera Studio
- Launch VH Multi Camera Studio.
- Click "Add URL" and in the "Select URL to capture from" editbox enter your rtsp:// URL.
- Hit the "Ok" button. You should be able to see your web-cam video now.
- Check the "Enable Output to VHMulticam Video Capture Device" and the "Default source (VHMulticam connects to this)" checkboxes.
- In Skype settings select "VHMultiCam" as your web-cam device.
This was tested with VH Multi Camera Studio 1.1.8 and Axis IP cameras using MPEG-4 video.