From Populous Wiki
With fraps, the resulting file format is uncompressed avi, which would need to be compressed using a separate piece of software such as VirtualDub or Any Video Converter. This will dramatically reduce the file size (over 100 times smaller), resulting in a file which is ideal for uploading to a web server. For further editing effects, windows movie maker or a similar piece of software can then be used.
However, recording full games would require a lot of space. In this case, using screenshots or small clips to make a video would be more appropriate.
If you are the host make sure your not slowing the game down causing the other players to lag.
A very useful set of tricks and glitches made by user Dakini Shaman by recodring content from Populous: The beginning The Dakini Shaman Youtube User Page