I\'ve encoded a few videos on http://www.theparkerpalmsprings.com to play using HTML5 when loaded via an iPhone or iPad. In my testing, everything works as expected when viewing
Please don't sniff User-Agent!
That completely misses the point of interoperability HTML5 tries to bring (and fails in my Flash-blocked desktop browser). and support automatic fallback and detection.
Did you encode video as H.264 Baseline Profile? Flash supports full H.264 (High Profile), but iDevices can handle only lower-quality variants (iPad & iPhone 4 support Main, older devices only Baseline. Similarily with AAC.).
If you ever add alternative format (WebM), put H.264 first, as iOS 3.2 cannot handle source selection properly.