I believe TG is correct. The 7D has two eye sensors just below the viewfinder but it has no grip sensor to activate the eye start, nor does it have a switch to turn on these sensors and I am unable to find a menu item that will turn on the eye start, or any mention of it in the manual.
The film 7 had all these things and if you were not holding the grip, the eye start would not function. This system prevented the situation described by minolta mad of the camera trying to focus when you're walking along with it over your shoulder.
If anyone can tell me how to turn on eye start on the 7D, I would love to hear from them. On the film 7 it was a great feature, but on the 7D, without the grip sensor, it could be a problem.
I think the A700 has eye start, but it also has the grip sensor, unless you live in Europe.
Or have I got it completely wrong.