The inability of iPhones and iPads to display flash has been a bit of a gamechanger in the world of web design. In the old days, flash was the safest way of displaying rich media in a cross browser, cross platform way. Nowadays, this isn't the case. You cannot use flash to display videos if you want people to be able to view it on iPads (although there are some very good alternatives like the open source, free Flowplayer which detects whether you are using an ipad and then displays the video content accordingly, or switches to using flash in compatible browsers).

Adobe may be publishing an HTML5 converter for flash, which if it works, will enable you to publish flash content as HTML5 - opening the doors to iPad/iPhone compatibility. The experimental technology is codenamed Wallaby, but not all flash features can be generated as HTML5. At the minute, Wallaby uses webkit CSS3 tags, so will only work on webkit based browsers (eg Google Chrome, Safari on OSX, iPhones and iPads) - this means that it will not work on the current versions of Firefox or IE. Actionscript 3 is not supported either, so you need to convert your flash to actionscript 2.0. This page shows the full compatibility list.