I've come up with the following solution: An Alix 2d3 with a Huawei E220 3G modem attached to it, and Zeroshell installed on the Alix. That all works well, Zeroshell connects to my VPN and I can place the thing in the church spire as they have electricity up there. We also installed a micro switch on a part of the clock that rotates once every 5 minutes, and we get a switch on / off from that micro switch.
Now comes the hard part: I need some sort of component that I can plug into the USB port of my Alix 2d3 and connect it to the micro switch so can capture the event, timestamp it and write it to a remote database.
Any ideas? Can I use something like a USB mouse and mod it?