I see this little proggie is still one the of most unknown little gems in the net.
Personally I've no idea why, so, here's the thread.
You will find it @ XPadder.com
Basically, what XPadder does can be simply described as: "it simulates keypresses and mouse movements using a gamepad
So, technically, I dare to say you can play *ANYTHING* using your gamepad, as long as the assigned keys don't cause a conflict with something else.
Technically (again) methinks this should easly work with those cool flash games
Personally, I also use it as a remote, when pluging in a psx joypad and sitting comfortably on me sofa watching movies.
A few example screenies from GooglePics: