Heinz, the new ringtone didn't extend the period of time, however, think of what I did this way:
The phone receives a prompt to ring.
*The ringtone I created has no delay from the beginning of the sound file to the time that it begins making sound, therefore, the iPhone starts ringing as soon as possible.
*The ringtone I created has a fairly loud initial "burst" of sound; the default ringtone on my iPhone was "Marimba", which progressively gets louder as the sound file is played by the iPhone - I sometimes wouldn't hear the iPhone until halfway through the second "ring".
*The ringtone I created has about 4 seconds of dead air space after the sound terminates - for each ring, I have about 4 to 5-odd seconds counting against me. The ringtone is loud enough so I can hear it from quite some distance away and has a "response time" optimized so that I have enough time to get to it (if I want to, that is?)
I custom-edited the ringtone (and a couple of others) so that I know that I have 6 rings before my caller gets voicemail. Still with me?
With AT&T, I get a period of time - 5-30 seconds. I set my ringtones to 5 seconds - 1 second of noise, 4 seconds of air: 6 rings and I miss the call.
What I don't know about Rogers - if its actually four ring signals to the phone, I'd work with that. Why not a 16-second-long ringtone? More to the point, call Rogers and find out what the period between ring signals is, then set up your custom ringtones to exactly that period, minus 1/2 second for each ring. In other terms, if Rogers tells you that each ring signal sent to the phone is 6 seconds, create one or more custom ringtones about 5-1/2 seconds long - you'll know right about when you'll miss your call and it's gone to VM. Work the system!
I'm checking out a docking setup -
http://www.phonelabs.com/prd05.asp - a couple of good write ups are around the web, a few - meh.
One tip I can offer. I learned with my VZ Treo, with it's speaker on its back, I leave the phone's speaker facing out when it's in my pocket. The iPhone? Always in my pocket upside-down now - the speaker's facing up and toward my ears when it's in my pocket! About that belt clip? You're on your own there, Heinz!
Have a two-four of Molson (or your choice) with some friends. You're in Lotus Land! Good luck, hoser!
Chris