I've connected a Caller ID capable modem to one of the serial ports on my web server.
When my phone rings the Caller ID is emailed to my cell phone.
The modem I'm using is a ZOOM Modem V.92 external (serial) Model 3049C
www.zoomtel.com
Configure:
AT+GCI=B5 AT+VCID=1
Result:
RING
DATE = 0829
TIME = 2141
NMBR = 1234567890
NAME = WIRELESS CALLER