Hi,chas_m, thanks very much. but quicktime supports flv? I thougt It suppoted mov. I'm confused now.
QuickTime has a native format, which is .mov, but it has always supported other formats, though the range was kind of limited.
The new QuickTime X, as included with Snow Leopard, seems to need very little help understanding the major standards of the Mac and PC worlds; it will play most AVI files, WMV files and FLV files without special assistance.
However, AVI (like MOV) is really just a "container" for many different types of codecs, not all supported, so I still recommend adding the (free) Flip4Mac Player
(allows almost ANY wmv file, no matter how funky, to play), Perian
(extends QuickTime's support to most of the other oddball formats, like MKV) and VLC Player
(which, together with the aforementioned, seems to play darn near anything and makes a good "alternative" player). All completely free of charge.