Requirements

There are some obvious hardware requirements to be able to use ShowSpeed, but also some software requirements.

QuickTime. On a Mac this is installed anyway, but if you want to use the manual procedure on Windows, you will need to install it. You may need QuickTime Pro, as using text-streams from the user interface requires that. However, many features of QuickTime Pro are available through the scripting interface, even if Pro isn’t installed. I have it, so it isn’t tested without it, but try it before spending € 30.00.
A means of reading your video file format in QuickTime. MPEG-2 requires an extra component if you want to add it to QuickTime. This is another € 20.00. Sorry about that.
For the nice tool: Mac OS X, version 10.4 or later.

The obvious requirements

A GPS device capable of recording a track-log. The GPS settings are discussed elsewhere.
A digital video camera compatible with QuickTime. Additional constraints on the recording technique is discussed elsewhere.
Movement.