At the same time? (same audio)
Yes it is
You need to jailbreak the phone and install after market software
This will of course invalidate your warranty
First, it will not invalidate your warranty, at least not the hardware. You can also always restore, and leave no trace of ever having been jailbroken.
Second, what is this aftermarket software you speak of? That information would certainly be helpful in this case.
Seriously.
I was under the impression it was a hardware limitation. However, if not I'd like to know
It wasn't always. Apple changed their views when the courts essentailly decided jailbreaking was legal.
No I mean the simultaneous audio output not the legality of a jailbreak, haha.