Here are a some of the best applications that currently support H.264 output.Apple QuickTime Pro Player 7
Not satisfied with just media playback, QuickTime pro supports a wide range of output options including Apple's own H.264 coded called AVC.
Price: Only $30
What's cool: inexpensive, Exports Apple H.264 QuickTime in .MOV format
Drawbacks: Lacks advanced encoding features, less "editor" more "player", no FLV support
Learn more: http://www.quicktime.com/
Apple Compressor 3
If you use Final Cut Pro to edit with, Apple Compressor 3 is a natural choice for encoding your videos for web delivery. Compressor's strength lies in its ability to encode using the Apple H.264 code, advanced encoding options, and batch processing. With presets for iPod, iPhone, Apple TV and more, you can also purchase the Episode Pro plug-in from Telestream which will allow you to encode Flash Video Files (FLV) and Windows Media (WMV) as well.
Price: Included with purchase of Final Cut Studio - $1299
What's cool: Exports Apple H.264 QuickTime in .MOV format
Drawbacks: Mac only, requires purchase of expensive Final Cut Studio, confusing interface, WMV and FLV require expensive add-ons
Learn more: http://www.apple.com/finalcutstudio/compressor/
Sorenson Squeeze Compression Suite
Now up to version 4.5, Sorenson Squeeze has come a long way. For years, the Sorenson Video 3 Pro codec was the de facto standard for QuickTime web delivery and Sorenson Squeeze was the only way to get the advanced codec features. Now Squeeze has matured into a full-featured encoding tool supporting a multitude of codecs including H.264/AVC and FLV (Sorenson Spark Pro, On 2 VP6 Pro) in a easy to use package. With its advanced batch features, intuitive user interface
Price: $499 (without On2 VP6 FLV)
With On2 VP6 Codec $599 (Windows), $749 Mac - includes Flip4Mac WMV9 encoder as well.
What's cool: Lost of included codecs to choose from (MOV, FLV, MPEG 1/2/3/4, WMV and more), batch encoding features
Drawbacks: Does not encode to Apple H.264 .MOV (MPEG 4 Only), expensive for non-professional users.
Learn more: http://www.sorensonmedia.com/