In conjunction with its latest QuickTime update, Apple has also updated QuickTime Broadcaster.
QuickTime Broadcaster 1.5.2 provides increased compatibility with Mac OS X Leopard and provides important bug fixes. The update ships in conjunction with the latest QuickTime update, which addresses serious security problems recently identified in the software.
QuickTime Broadcaster allows users to produce live broadcast events. Features include: H.264 (MPEG-4 Part 10 video) live broadcasting; 3G streaming support; "dramatically improved performance" for streaming 640x480 30fps video and increased standards support including 3GPP and ISMA (Internet Streaming Media Alliance).
The 1MB update is available here.