Its a bit like how much of the time do you spend chating in the office - i talk to colleagues all day long as i go about my day to day tasks but only spend 1/2 an hour a day actually in formal meetings.

So the answer would be 9 hours a day at work and 3 hours at home for logged in time about 1/2 an hour a day actually typing tweets or RT or DM's. may another 1/2 hour reading tweets in 1 minute sessions through out the day.

It certainly is difficult to quantify. I get asked this all the time so I threw some pointers here on the ambition forum.. http://getambition.ning.com/profiles/blogs/how-much-time-should-you-spend

I will often take a quick peak and nothing more.. this is only seconds. Other times I am engaged in over an hour catching up on what those in my networks are doing.

If i had to put a figure on it though, I have said around 3 hours a day.. I do not work in an office and constantly have a second screen open. I do see more and more people working like this though.

Cheers for the comment.