For those of you who installed Quicktime 6.5.1 and QT broadcaster, you might notice that it doesn't work. Don't worry, most people I talk to are experiencing the same thing.
Though its GUI isn't as pretty, and the options are more limited, Darwin Streaming Server [10.1mb download] includes a broadcast server that seems to work great. Plus you don't have to drop a grand on OS X Server! I've got it working with little setup and am watching TV on my G3 via my G4's FireWire A/V IO box right now.Here is a direct download link.
Note: you must be running 10.2.8 or higher to use this software, and you'll need to login to Apple's Open Source site to use the above download link.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20040501111728945