Flash has not performed well on mobile devices. We have routinely asked Adobe to show us Flash performing well on a mobile device, any mobile device, for a few years now. We have never seen it. Adobe publicly said that Flash would ship on a smartphone in early 2009, then the second half of 2009, then the first half of 2010, and now they say the second half of 2010. We think it will eventually ship, but we’re glad we didn’t hold our breath.

You can't teach common sense, but this open letter from Steve Jobs regarding Adobe's Flash makes the attempt. What Mr. Jobs mentions above is constantly forgotten or ignored by many even fairly technical people that should know better.
There are no mobile devices that run Flash. Period. There will be... fine. But we have open standards today that don't require flash, and any web development shop worth a nickel already creates "no flash" alternative experiences for any site they develop.