Chuck Fadely offers up a good tutorial on encoding video into Flash (the only way you should be publishing video on the web).
If, for any reason, you don’t have the software/hardware (it’s takes some time and horsepower), the guerrilla tactic is to use Google or YouTube. You save your video in one of the supported formats (check the upload instructions on either site), and let Google pay the processing price. I prefer Google video because the quality is better and you don’t get the “YouTube” watermark on your video. Google also offers an upload tool, so once your video is uploaded, you can walk away, shut off your computer and do something else. Google will e-mail you a link to your video after it’s encoded. The one disadvantage of Google is there’s a price for the better quality Flash — it’s a bigger download, so people will even a hint of a slower connection will find it harder to watch.
Again, that’s a guerrilla tactic for those producers who have no other way of publishing in Flash. It is better to publish into your own player, but it is better to publish through Google than to subject users to a WMV or QT file, because with either format, you risk shutting out some portion of your audience.