Cool idea. Most Flash pinball games have terrible physics though.. what are some good ones?
I co-designed and programmed an online pinball game a while back. It used the Shockwave plugin (pre-Flash) and the no-longer-supported Havok physics Xtra which means almost no one can play it anymore. Bummer!
http://www.cheezywhiz.com/stroker-and-hoop-moneyhot-pinball/