I managed to use the Wayback machine to get Overviewer and HMI Player from a 7-year-old cache of TexMurphy.com, and I've uploaded them on filexoom for easy access (you need HMI player in tandem with Overviewer for full functionality)
Overviewer: http://filexoom.com/files/2006/12/17/49066/ov120.zip
HMI Player: http://filexoom.com/files/2006/12/17/49066/playhmi.zip
Overviewer: http://filexoom.com/files/2006/12/17/49066/ov120.zip
HMI Player: http://filexoom.com/files/2006/12/17/49066/playhmi.zip