Yes, it's the dominant video format on the Net, largely thanks to YouTube, and it certainly downloads quickly. But the quality of Flash video often leaves something left to be desired, particularly compared with the crisp, clean resolution of MPEG-4 H.264, which I and many other video bloggers use for our own vlogs. Plus, H.264 is a cinch on Macs, which makes sense, because it's the preferred format of Apple's AppleTV technology.