is there any way to bust through someone's phone line when it's busy...
 

other than using the operator?

Not that I know of. They do an emergency interrupt and charge you. Don't know of any other way to get it done. Unless they have call waiting.

Only an operator can do it, and only if it's an emergency(some states have laws against doing this if it's not a bonafide emergency). And they can't do it if it's a cellphone, only a landline.

Its called a "Busy Override" feature. There are only a couple phones I know of that have this circuitry and you have to be in law enforcement to order them.

i just dialed 0 and gave them the number i wanted to call, and my friend's landline to charge it to. so after my friend accepted...they put me through to a busy signal! wtf??? only thing i can think of is maybe the phone is off the hook...

Who doesn't have call waiting or voice mail in 2005?

maybe those in the third world

with my experience in telecommunications,
the only way to do this is to knock on their door