For OGG on Windows: Theoraconverter
VLC should be able to do this.
The Miro video converter does a beautiful job and is drag-n-drop. http://www.mirovideoconverter.com/
BTW it's FREE and also very good for mobile device encoding.
MS Expression Encoder can do mp4/h.264. not sure about ogg though.
Source: Stackoverflow.com