I've been thinking. (I know, head for the hills!) What with technology, it's only a matter of time before we see an "Outed myself by mistake with my videophone." thread pop up. We should start a pool!

More likely that someone has their phone in their back pocket and butt-dials a friend while at a support group meeting. 

I make sure I cover myself. Sense my parents, employer and most of my friends are unaware of my transition (soon to be). I use a secure browser and make sure i clear all "evidence" and when Im on a computer I do basically the same thing just even more cautious.

I must admit, not being full time, when I'm in public as a woman and I receive a call from a friend I have to consciously think about what voice and mannerisms I'm going to use.

I'm sure there are plenty of people who have answered in a very feminine way when they weren't yet out to that person.