About 30, but I am going to keep only the once I can see myself developing. I am always looking for new domains, but only buy if I see myself doing something with it.
i only register domains i think i can do something with (apart from 1 night when i bought 3 LLLL.com's). so currently 34, 5 are ative and 8 are being worked on atm. the rest are on sedo waiting for me to make them into a site or get a good enough offer.
~360 domains, maybe 30-50 live sites. It was getting a little out of control to manage all of them across various registrars too. I made a web-based domain management tool for myself - only been using it a week or so. I think it will be a big help to me.