It is an app/company apple bought. They then allowed it to tie in with their private api's. Nobody should defend their move to lock it to the 4s, period. There aren't technical reasons...they just don't have nothing else they could force the upgrade with. Isn't this an original iPhone...yes, I think it is. http://www.youtube.com/watch?v=AohzWSkAU7c&feature=youtube_gdata_player So fine, it's cool if you like the 4s, but I can't count how many posts is read today where people act as if a)apple made Siri or b) there's some reason fruitco can't have it run on older devices. It's the holdback to compel the upgrade, that's all. I expect a jailbreak will remedy that at some point.