Electronic Alarms and Home Security Devices - Cell phone connection to security panel

I'm curious to know if there is a way to connect an old working cell phone (with service) to my security panel, if I do have a phone interface and voice module. I know that it connects via RJ-31X jack, but is there a way to somehow connect that to a cell phone with some type of adapter?

I'm familiar with the Cellular Backup Transceiver/devices but that usually has to go along with a paid service with a company, right? Isn't there a way to just have my old cell call out from the security panel? I imagine it should be possible. Could you just reprogram the Cellular Backup Transceiver?

This was just an idea I had, since a phone line seems like the weakest link in a security system (unless you have a monitoring service). Since it is outside of the house, unlocked and available for the local utility companies and anyone else for that matter. I doubt the phone company would allow people to put it behind a lock.

A cell phone connection just seems safer, unless the thief has a cell blocker that is...

It depends on the cell phone, for sure, and one a lot of other factors (it would have to be a phone that can act as a modem). Basically, the cellular dialers are specifically made for this purpose.

I know that some of the modern cell phones have hardware add ons that let you plug them into your landlines in the house, but I'm not certain if that would work or not. Alarm communication can be almost as fussy as computer communication.

So do they have programmable Cellular Backup Transceiver/devices? Or do they only work with the paid service companies? If I can just plug in my emergency #'s into one of those and forget about a service, that would be most advantageous.

There is at least one such beast, but I warn you, they aren't cheap...

Cellular voice dialer unit (http://www.unitedsecurity.com/New%20Products.htm#USP)

Thanks for the info MrRonFL. With the popularity of cell phone technology I figured they'd have more options...

I'll also look into hardware accessories for cell phones.