Pseudo streaming h264 is a bit trickier than a dozen lines of PHP, although that works for FLV files (I'm assuming you've got your h264 in a .MOV-like container here, since that's what's recommended). You'll need to create an updated file header with new offsets to samples, which is a bit more work than "add a FLV header and cat the rest of the file".
The good thing is that it's Been Done for most servers (mod_h264_streaming modules exist for practically everything under the sun), so one rarely has to reinvent the wheel.
See e.g. http://h264.code-shop.com/trac/wiki/WikiStart