If videos simply aren't available in HTML5 and you HAVE to watch them on your iPhone or iPod Touch, here's a solution. Skyfire is a web browser that allows you to play Flash videos on your iPhone and iPod Touch. It doesn't work on the iPad however.
Skyfire uses a cloud-computing platform to translate videos from Flash into an iPhone friendly format. Certain websites, however, like Hulu (even after you've used an IP mask), don't allow it. This browser only works for video, not games and applications.