There was a Flash hack available a while ago. I think it was working (barely) on the iPhone 3GS.
The main issue is that the Flash technology is not optimized for devices using low energy consumption and most Flash apps/games do require a keyboard/mouse as input. I have the PlayBook 16Gigs which supports Flash natively. Basically, games are not working because there is no "keyboard" input available. What I mean is that when you display the virtual keyboard, you hide the app, and vice-versa...
The only really useful Flash app that do work quite well (at least on my Playbook) are those made for broadcasting the webcam (Like Justin.tv, Stickam, etc...). It's hard to chat, but the video capture does work well.
A few months ago, Adode has declared that Flash for mobile devices was to be obsolete in a near future. So that may also explain why hackers are not putting any effort on this implementation since it will disappear anyway by it self.
In the mean time, search this forum as there is a lot of workaround for accessing Flash based website (I use iSwiffer mainly when there is not other way)...
Have fun!