I believe the term is chakar or chakram. ( one or other or both) They can be carried/worn over the head(turban) as added protection or thrown. Being a circle they symbolise the endless cycle of life and god .
Here is an interesting link to a video about Sikh warriors you may find interesting. It is not the video Puff is refering to, but there are scenes with many familiar weapons
http://video.google.com/videoplay?do...89731&q=nihang
or a longer one
http://video.google.com/videoplay?d...03&q=nihang