The answer to your question was sitting in a Sticky thread at the top of this section. But you want to be baby-fed.

Get VLC - (click on link) _ (choose nearest mirror site)

To see what it can play see http://www.videolan.org/vlc/features.html You'll notice it can also play numerous audio formats & can be used for video or audio streaming such as online radio. You can also downld extra skins for it. AFAIK it isn't an image viewer so can't open jpg.