Nice article on building a webcam with pan/tilt and a Raspberry Pi all managed over 3G network. It lacks a bit on the tech (how he did it), but interesting all the same. It also has a bunch of other sensors included…my 2 cents, this is in the UK so phone lines are pretty cheap…not so in US, so odds are I would not put this on the phone. Really wish there was more tech in this article too.
http://projectsmax246.blogspot.co.uk/2013/01/webcam-over-3g-with-raspberry-pi.html