As scrap said you have to be carefull. Because of the nature of the exercises the momentum caused by them is likely to move your joints past there boundrys and cause you injury if you do not stretch off and warm up before and after doing them.

A good Plyometric exercise for Conditioning are 'Burpees':



[stream=380,320]http://www.momentumsports.co.uk/media/movies/MKBBurpee.wmv[/stream]

Upper body power, clap press ups:

[stream=380,320]http://www.momentumsports.co.uk/media/movies/MKBClapPressUp.wmv[/stream].

When I get a minute I'll list some more...