For me... wayyyy too much. I run my own website, which I work on a lot. I also work for a friend of mine, so I work on her website and write for it quite a bit (probably more than on my own). I recently finished her redesign and the redesign of her mom's website, which took some time. Now I'm looking for other work from home type positions.
Needless to say, I spend most of my time on my computer... I'm a geek!
I need to set up some sort of schedule because everything related to my site is getting pushed behind everything else...
I need a vacation!
I think that I spend about 4 to 5 hours a day online. But I like to write contents for the different sites and I think seriously about creating eBooks.